In Mediterranean countries most available or accessible water resources are already exploited. Considering that the irrigated agriculture sector annually consumes up to 80 percent of water resources, and up to 90 percent in the peak demand period, every small decrease in this consumption will make more water available for other uses and reduce conflicts.
To promote this objective, governments are implementing policies based on tariffs and quotas, as well as modernization programmes to improve equipment and practices (Molle et al. 2004).
After years of massive investment in large infrastructures (Bouderbala 2004), governments now prefer to provide support to small private farms. Such support appears to be more cost effective per hectare, it allows farmers to become involved in the economic process, it helps to settle rural populations and it contributes to the development of local industry in rural areas while promoting extension service infrastructures dedicated to farmers (Gadelle 2002).
Moreover it appears that modernization policies that target farms are more successful when seeking step-by-step improvement, rather than through revolutionizing practices (Kay 2001). Participatory management systems that involve farmers give them a greater stake in system operations, which facilitates communication between the farmers and policy-makers (Loubier and Garin 2006). This implies creating farmer associations that allow end users, managers and political authorities to interface (Spadana 2004).
Modern irrigation techniques certainly have the potential to improve water and human power productivity. But their introduction is mostly driven by commercial stakes rather than water-saving concerns (Brabben 2001).
The financial and administrative tools employed to help manage irrigation systems have improved situations, but on-farm system durability remains too poor. To be effective, modernization policies should be based on an integrated analysis of current situations and practices, encompassing different levels of scale from farm, network to river basin (Vidal et al. 2001).
The farmers' priorities are often very different from what other stakeholders think. These differences may lead to conflicts or at best misunderstanding. The recurring problem is that farmers are not well represented, so their expectations are not considered by other stakeholders, or through the "filter" of other experts.
With this in mind, the Inco-Wademed Concerted Action was developed to: (i) Assess water management experiences in Maghreb countries, (ii) identify factors that hamper the implementation of water-saving measures and (iii) put forward recommendations for improving water demand management policies. To this end, a database of water management modernization experiences and their results has been created (www.wademed.net). A first workshop entitled "Modernization of irrigated agriculture" organized in Rabat, Morocco in 2004, focused on the exchange of experiences concerning technical issues. Recommendations
1 CEMAGREF (a public agricultural and environmental research institute) France. Email: firstname.lastname@example.org
proposed during this workshop are widely referred to, and commented on, in this paper. Two other workshops were organized on the same principle in Tunisia (2005) and France (2006) respectively on "Institutions and policy-making" and "Implementation of participative water management solutions".
In this paper, the modernization of farm irrigation systems will be assessed. The main focus will be on farmers and their interaction with water managers, policy-makers, equipment dealers, manufacturers' policy or product processors.
By modernization of on-farm systems we mean principally the conversion of farmers from traditional to supposed higher performance (i.e. modernized) practices and techniques. This is understood as the operation of water-saving technologies, most often the use of micro-irrigation, sometimes the implementation of irrigation scheduling. All of these factors should allow water to be saved provided a number of conditions are fulfilled.
2. Farmers and water management
Farmers expect the water manager to provide them with a reliable water supply in terms of volume and time scheduling. The modernization of irrigation systems usually involves adjusting water-application timing of irrigation equipment to plant water demand, both of which are linked to climatic and water supply conditions.
With unreliable water supply, precise irrigation scheduling methods cannot be properly implemented, even if the annual water volume at the farmer's disposal is sufficient. However the principal criterion used by water managers to evaluate their own level of service is more monthly volume supplied than daily or at least weekly supply, consistent with plant water requirements throughout the cropping season. Any insecurity in water supply will lead farmers to implement precautionary water management strategies that integrate variability in supply.
In pressurized systems, when the farmer is not sure about the next date of water delivery, he will maximize water application when water is available to fill the soil reservoir and wait for the next water distribution shift (see Plate 1). This will obviously lead to leaching or drainage and salt contamination of water tables. In Plate 1, the farmer's behaviour results in unreliable hydraulic parameters and jeopardizes good application performance with pressurized systems for those farmers who are more distant from the pumping station.
Plate 1. Filling up of a soil reservoir
The same issues affect gravity systems as irrigation techniques cannot be effectively improved when irrigation intervals are so long that the water holding capacity of the soil cannot provide enough water to plants between irrigations.
To secure water supply when possible, farmers operate private pumping facilities or storage, even if this water is saline. Thus, depending on the water supply schedule, networks will be considered as a mitigation solution (the coastal area of Doukala, Gharb, Tadla in Morocco). This may contribute to soil salinity and related water table depletion due to salt leaching.
If a reliable water supply is not guaranteed water supply cost recovery will become a problem. The farmer will hold the water manager responsible for his income decrease and he will not accept charges for a water service that does not allow him to obtain good production results.
Consequently the water manager will delay system maintenance, thus leading to lower levels of service and reduced cost recovery (Mouhouche and Guemraoui 2004). This vicious circle must be broken. The participatory path seems the more powerful and cost effective way to bring about changes, involving all stakeholders' representatives.
For the Tadla irrigation system (Morocco), the local water management company has developed dialogue with water users through Association Tadla de l'Irrigation Localisée (ATIL), a water users' association (WUA) that it helped to set up.
Thanks to good levels of water distribution, equitable water allocation practices partly rely on the development of private storage (Plate 2) and cost recovery is higher than 95 percent. The canal-based distribution system is able to provide a service approaching on-demand supply. Each farmer is allocated a yearly quota based on water available in the reservoir. Micro-irrigation users are allocated a higher quota than those using traditional techniques.
Plate 2. Private storage tank, Tadla, Morocco (for a 65-ha citrus farm)
An allocation system based on water order forms has been implemented through the ATIL. This lets farmers co-manage their access to water. They share local water distribution shifts that are based on individual requirements (micro-irrigation users have different water quality requirements to those of surface irrigation users) and private storage capacity.
The problem is that equity is not really achieved because:
Such a policy intends to accelerate a switch to pressurized irrigation systems, but in fact it favours farmers with greater financial resources and may result in an increased rural exodus of poor farmers. An adapted financial support policy may prevent such an adverse effect from happening.
In the Moulouya irrigation system (Tizaoui 2004), the Mohamed V dam supplying water to the area is partly clogged with sediment, reducing its capacity to 45 percent of its original value. The water management company, in cooperation with the government, has helped farmers to design and manage private storage tanks that are geo-textile lined and to modernize their irrigation techniques. These tanks represent a major cost which doubles the total investment compared with that required for the plot distribution system alone. Subsidies amounting to 40 percent for individual farmers and up to 60 percent for a minimum of three associated farmers are provided. This operation has improved the scheduling of water supply to single farms. Lastly the more secure water supply provided by individual storage, along with the implementation of quotas and associated modernization of application techniques, has freed up approximately 30 percent of former volume, which can now be used by other users. This is mainly due to the decrease of precautionary practices (excess water application when available), increased water use efficiency and modern scheduling methods. The local water management company has created an extension service which is a key player in this successful modernization process.
In Tunisia, to improve poor farmers' access to modernization, the government operates cooperative measures such as higher subsidy rates (60 percent) for these farmers (Latiri 2004). Such cooperative solutions could be extended to all types of agricultural equipment providing a legal framework is implemented.
In areas without networks, management will concern the water table. Basin management authorities are responsible for such management. Pumping authorizations are delivered accordingly, but, due to overpumping or changes in management policy, new authorizations are no longer given. The consequence is an increase in unauthorized pumping (which is sometimes subsidized!) and greater difficulties in resource management. The basin authority will be forced to applying tougher regulations that may negatively impact profitable farming activities and may result in social unrest or prevarication by the authorities.
In 2002, in the valley around Damascus in Syria, overpumping by 20 percent over the last ten years has led many farmers to move away from their farms due to an increase in water table depth, which exceeds 100 m in some places. In 2006, the termination of pumping authorizations did not generate a reversal of the situation.
The same situation occurred in the Upper Barada Valley, close to the Lebanon border. The regional authority intends to create large wells and to use them as a means to control farmers' water withdrawals. These policies, which promote a "natural selection" process leading to the departure of poorer farmers, may allow the system to find a new balance, but generates considerable money wastage, firstly for farmers, especially when they have invested to modernize their irrigation systems, and secondly for the government when financial subsidies have been allocated. Even if conflicts fail to erupt, social tensions exist.
In Morocco, in the coastal areas of the Gharb Basin, private farmers have developed fruit and vegetable farms on sandy soils, pumping from the water table. Land is rented by "nomad farmers" who are not concerned about environmental sustainability. After ten years of major expansion, salt intrusion, nitrate and pesticide pollution are beginning to cause technical problems, along with pest pressure.
Local farmers have urged the basin authority to handle the situation, but the economic stakes have slowed down any initiative. The region is very economically dynamic and exports mainly to European countries.
3. Farmers and policy-makers
When access to water resources becomes difficult, farmers usually expect policy-makers to draft regulations aimed at fostering water allocation equity. Equity in allocation is one of the aims put forward by policy-makers, but it is seldom achieved.
3.1 Access to water
Generally when water becomes scarce or is inequitably distributed or when water distribution is unpredictable from public networks, wells dug without authorization multiply and governments stop delivering new pumping authorizations.
This situation was observed in Syria (Molle and Laiti 2003), where only one-third of the 180 000 existing wells were authorized. These wells irrigated about 65 percent of agricultural plots using one-third of the water resources of the country. Overpumping by 20 percent resulted in the drying up of one-quarter of the wells, which contributed, in a certain way, to pumping regulation but it did not improve the situation. Volume uptake control may be the only way to manage water tables.
In the Parisian Basin in France, where the water table is under high pressure, every water withdrawal point is equipped with a water meter. Each farmer is allocated a yearly water quota. This management system requires knowing water table reaction to rainfall and withdrawals and good cooperation between all stakeholders. Withdrawals are declared annually by the farmer to the river basin authority, and are randomly verified.
This management method resulted in the preservation of the water table level, despite three successive years of rainfall deficit (2003 to 2005). A 25 percent reduction in water quotas did not generate a significant decrease in yield. These results are attributed to two factors: Quotas have been defined as comfortable and on-farm irrigation performance has progressed (AND-I, Cemagref 2006).
Landownership with regard to water access is also an important issue. Access to water resources is commonly linked to landownership which leads to numerous murky practices and related waste risks. In Syria (Molle et al. 2003) landownership is somewhat informal; many plots have been sold or inherited, without official registry to avoid paying taxes or administrative duties related to such transactions. Thus when farmers want to register their wells it is not possible, even if the previous owner had authorization. Consequently water uptake estimates are impossible due to lack of transparency.
When the farmer rents the plots he cultivates, and when contracts do not exist or are only yearly, the farmer will not be able to access water with transparency. In the meantime he will not attempt to adopt costly and complicated water-saving technologies and practices. This leads to uncontrolled water uptake and bad management practices, as mentioned previously for the coastal area of the Gharb.
Rules on pumping authorization should be clarified. Pumping authorization must be accessible for all farmers along with appropriate metering. This will make it possible to assess volumes with a minimum degree of accuracy. Once this is established, effective water management is possible through quotas or water pricing, which will have different impacts on irrigation technique modernization (Montginoul 2004).
3.2 Access to financial support
Developing modern water-saving techniques requires a minimum level of investment. Usually in developing regions, farmers have limited financial means, and will thus need access to subsidies or low rate credit to help finance modernization.
To gain access to credit, farmers have to be familiar with banks and their administrative processes. Only educated farmers possess this knowledge and smallholders need assistance. This was observable during the Syrian modernization programme in 2002, where less than 5 percent of available low rate credit was effectively used by farmers after two years of the programme.
When subsidies are offered the problem remains the same; the first candidates are those who do not really need such support. The smallholders apply later in the process and in some cases cannot gain access because of attribution rules.
We have observed this in Morocco and Tunisia (Molle et al. 2004), where subsidies were allocated to farmers modernizing their systems (40 percent of cost). Subsidy policy is framed in such a way that under 5 ha, projects are not cost effective. In Morocco, during the first 15 years, the average size of subsidized projects was 16 and 12.5 ha respectively for micro-irrigation and supplemental irrigation projects (AGR 2003). Then the government decided to allocate subsidies to complete systems (storage, pumping, distribution) and the average surface area decreased to 7 ha in 2005.
Observing that smallholders could not access these subsidies, the Tunisian Government decided to increase the rate of subsidy by 60 percent when at least three farmers present a joint subsidy application. This was successful thanks to the help of extension services (CRDA) in designing consistent and cost-effective projects.
Another point of concern regarding modernization subsidies is cost recovery. Support for modernization is often considered by farmers as a gift and not as an opportunity to help build a cost effective and productive production system. This results in neglected equipment and maintenance as noted later.
The help of extension services is the key to reaching sustainable modernization. They are very active in Tunisia as well as in Morocco. In Algeria now that the political situation has become more stable they are being progressively re-opened.
Extension services help farmers' decision-making on project dimensioning, they validate dealers' sales propositions, suggest changes in system design and participate in project inception. Their agreement is needed before subsidy allocation.
The extra work required for such a verification mechanism should be recognized and financed by the modernization programme.
Such subsidies and technical support policies have allowed Tunisia to increase the total surface covered by micro-irrigation in 2003 to 22 percent of the irrigated area. But these subsidies and support also cover other modern irrigation techniques whether pressurized (sprinkler: 27 percent) or not (surface irrigation: 25 percent). Water losses have decreased enormously; Vidal et al. (2001) cited up to 50 percent decrease in such losses in citrus production areas.
In Morocco the subsidy policy extension to private storage tanks decreased the pressure on public networks and created a water resource buffer capacity close to the areas of consumption. In Tadla management area it represents 4 percent of annual volume used by pressurized systems and gives an autonomy of ten days.
Where water distribution shifts are too long, such solutions helped achieve resource reliability.
Plate 3. Combined irrigation system to produce wet bulbs in the soil
3.3. Consequences of modernization: Identifying policy priorities
The definition and conditions of subsidy allocation for modernization are keys to reaching policy objectives. We can identify three priorities in modernization policies, generally given in the following order:
Modernization of irrigation techniques may result in considerable changes in the existing balance of the hydraulic system. Where traditional irrigation methods are modernized the existing beneficial losses will drop to zero. Increasing water use efficiency increases net water consumption, decreases leaching and associated water transfers to downstream users (Molle et al. 2006). Depending at what scale water use efficiency is considered, modernization of plot irrigation can be considered either good for the individual farmer or bad for the balance of the aquifer.
Lastly the sustainability of modernization policies should be questioned at all scales from farm to regional level, considering employment, incomes, rural activity and social welfare to achieve regional sustainability.
As mentioned previously the help of WUAs will allow modernization to become more consistent and integrated. To be sustainable these WUAs should have financial and decision-making autonomy; this implies an appropriate legal status and matching rules.
Numerous tools exist to help such processes, such as Olympe (Le Grusse 2001; Carmona et al. 2005) and can be used in participative analysis before any policy decision.
4. Farmers' expectations of irrigation equipment manufacturers and testing laboratories
4.1 Quality and durability
When governments actively support farm irrigation modernization policies, an expansion in the number of local dealers, installers and manufacturers usually follows. For example in Syria in 2002 approximately 140 irrigation manufacturer were registered, for an irrigated surface area of 1.35 million ha of which 0.2 million ha were under pressurized systems.3 This is definitely excessive, and results in intense competition, which often leads to bad commercial and manufacturing practices.
Manufacturers will lower irrigation product quality to reduce production costs. As most equipment is manufactured from plastic compounds, they will buy low-cost raw materials, use low quality recycled plastics and save money on additives.4 Product durability will thus be reduced.
Such situations will weaken "good" manufacturers because of unfair competition and generate considerable money wastage that may be fatal to smallholders with limited financial means.
The first step required to improve irrigation product quality is the development of a testing policy that establishes real performance characteristics within an independent laboratory using standardized protocols.
2 Total irrigated surface area: 162 000, 25 000 and 75 000 ha direct and indirect employment. Source: Bouches du Rhône, Regional Authority, Marseille.
3 The same numbers were reported in 2006 during the symposium.
4 Protecting plastics from oxidation.
The government plays a key role in developing such laboratories and promoting quality verification mechanisms linked to modernization policies.
In Morocco between 2002 and 2004, the simple fact that testing of products to be subsidized was made compulsory resulted in an increase in dripper quality (Laiti et al. 2004): The highest quality class represented 60 percent of tests in 2002 and 72 percent in 2004.
Such a policy, conducted on new products after standardized sampling, is to be extended to products taken randomly from the field after installation to avoid any discrepancy between products evaluated in the laboratory and located in the field. Testing, which can be very simple, could be conducted by regional extension services at a very low cost.
4.2 Standardization and testing
Implementing a standardization process will help involve manufacturers more heavily in this quality policy. It provides a framework that allows all stakeholders to reach a consensus on different technical aspects of irrigation. This process is managed by a standardization committee comprising all stakeholder representatives. This committee should be balanced, as achieved in Morocco (Molle et al. 2005), and not monopolized by one category of stakeholders. It can be further consulted as a reference group on evaluation of modernization policy in a totally transparent way.
Moreover the standardization committee is in a position to help identify regional technical stakes and define R&D needs, bridging the gap often observed between field evaluation and academic research concerns.
The standardization process relies on references obtained by independent laboratories which verify the levels of performance of irrigation systems or products with those put forward by manufacturers. These laboratories should be public to avoid commercial pressure. A small amount of modernization programme funds could be put aside for this purpose. From our experience creating independent irrigation testing laboratories is a cost-effective water-saving initiative, provided they are closely associated with the modernization programme.
These laboratories should have resources to operate tests and integrate an international network for benchmarking. This is what INITL5 is attempting through cross-testing, information, sample and methodology exchanges (INITL 2005). Recently this network was recognized as a key partner by the International Commission on Irrigation and Drainage (ICID) and also by ISO SC18 "irrigation techniques" for standardization processes. The results obtained in the framework of a cross-test on sprinklers (11 laboratories in the world) were integrated in the new revision of ISO 15886-3 on sprinkler testing.
With regard to the development of regional laboratories, they should take advantage of close cooperation with universities to develop staff skills through R&D cooperative studies in association with local manufacturers or dealers.
4.3 Quality in manufacturing and installation processes
As most irrigation products are manufactured from imported plastics, manufacturers should create their own quality assurance processes to verify the characteristics and quality of compounds they will use in their manufacturing processes. The implementation cost of such verification laboratories requires a minimum manufacturing plant size to be effective. It can be externalized provided that it is justified by market demand. In Syria in 2002 negotiation between manufacturers and the Damascus Chamber of Commerce was initiated to create a small private laboratory dedicated to plastic material testing. In 2006, without any willingness from the government to operate a quality policy, nothing had been made.
This will certainly contribute to cleaning up the market, reduce the number of manufacturers in Syria based on quality and performance criteria but it will also contribute to saving considerable amounts of private as well as public money and people's energy.
5 International Network of Irrigation Testing Laboratories: 21 members in 2006 (CENTEC Australia, Brazil, Canada, China, Egypt, France, India, Italy, Israel, Japan, Republic of Korea, Malaysia, Mexico, Morocco, Portugal, South Africa, Spain [2 laboratories], Syria, United States, Zimbabwe).
The competition among dealers to provide cheap solutions for poorly educated farmers will inevitably lead to lower system quality. In Morocco and Tunisia the government has linked subsidy attribution to equipment or system design quality verification for field systems. Subsidies are given to systems verified by regional extension services (from water management companies or regional agricultural authorities) and after system installation in the field.
Such verification processes have been very effective in Morocco in support of subsidy policy for farm irrigation systems. They lead to better system design (as illustrated further) and reduce the number of incompetent system installers.
4.4 Technology transfer
Equipment modernization is generally associated with more complicated operational processes. It requires specific skills that farmers may not possess. The consequence is often that the dealer must offer an extension service role when selling his equipment.
To avoid such distortion, the government should link the allocation of a share of its subsidies to technology transfer as it is an integral part of the modernization process. The implementation of a technology transfer framework should be managed by the national laboratory in cooperation with extension services. Technology transfers will be needed for the field operations of modernized systems and subsequently for maintenance of the systems.
It is the responsibility of the dealer to tell farmers how to maintain their systems so that a satisfactory level of durability is attained. Documents to this effect should accompany system delivery in addition to hardware. In Morocco, subsidies are not attributed if these documents are not provided.
In micro-irrigation systems for example, if maintenance is satisfactory, system durability should be more than ten years. In France the average value is often lower than five years. The main reason for such poor durability is bad filtration characteristics and incorrect maintenance which lead to partial clogging of drippers. When the farmer is not aware of the deterioration of system distribution performance, observing locally grown plants showing evidence of scarcity, he will consider applications to be insufficient and increase irrigation duration. In Tunisia, Mailhol et al. (2005) measured water efficiency under three-year-old dripper systems and discovered that 50 percent of them were less efficient than some traditional surface systems.
A long-term reference study conducted in South Africa (Reinders 2003) on 42 plots showed that after the second year of operation, 67 percent of pressure regulating drippers and 42 percent of non-regulating drippers were clogged (i.e. the flow rate had changed by more than 20 percent). A training programme for farmers that focuses on maintenance processes is now underway and managed by the national laboratory of ARC in Pretoria.
4.5 Appropriateness of modernization policies
To ensure that modernized irrigation options are adapted to local conditions (water quality, reliability of supply, availability of spare parts, farmers' skills, farmers' financial capacity), a thorough investigation should be carried out prior to any modernization of field irrigation systems. The national laboratory will prepare guidelines for modernization in different contexts based on existing experience. Such a process has been successfully implemented in Morocco to prepare guidelines on field irrigation systems' design and their field installation. These guidelines are to be used by extension services and are being standardized in Morocco. This could easily be applied in countries with similar climate and water supply conditions.
If the modernization of farm irrigation systems is supposed to be subsidized the rates applied must be fitted to the local financial conditions. The objective is to obtain an important lever effect by attenuated financial incitation apropos irrigation cost. In France irrigation costs represent approximately 20 percent of the total cropping costs, among which 50 to 70 percent represent equipment cost for centre pivots or hose reel guns. As a consequence subsidies applied to equipment will incite renovation of equipment, representing a small part of the investment; this can have an enhanced effect on the productivity of the system and on water productivity. The degree of incitation will depend on the proportion of the subsidy related to the cost of equipment, the maximum amount per project and the technical rules applied to access the support.
Finally the modernization policy should be evaluated periodically and revised if required. A set of indicators is needed to evaluate changes in farm performance in terms of water and more generally input productivity, incomes and cost recovery. Indicator ranking will comply with modernization policy priorities.
The use of actor models (Le Grusse 2001) can be very helpful for identifying gaps in modernization processes as well as anticipating the consequences of policy decisions at the farm scale, and then at the small region scale in terms of production, productivity, income and employment.
5. Processing and marketing of farm products
The priority of the farmer is to assure a minimum level of income for his family and venture. His production strategies are subject to this objective. Small family farms prefer to ensure daily income, while bigger farms will seek credit for investment to obtain higher profits and to meet longer term objectives.
Small farms will diversify production to ensure regular incomes (producing milks, poultry, eggs and vegetables for example) while bigger farms will focus on making profits.
Generally the small farms are connected to local markets and not to industrial or export networks. Production is usually variable in terms of quality and quantity. These farmers are not organized, are subjected to the constraints and fluctuations of the market and are unable to secure their production process.
They may grow some specific crops to access water. For example in Morocco sugar (beet or cane) or milk production allow access to water rights (notional strategy). Part of this water is then diverted to other more cost-effective crops.
These farmers mostly use traditional surface irrigation techniques. They will convert to modern techniques if they are obliged to. This occurred in Moulouya (Morocco) and in Tunisia for water scarcity reasons, or implementation of quotas.
On the other hand, larger farmers or dual activity farmers will specialize production and contract with the food-processing industry based on quality and quantity requirements. They are contractually obliged to implement specific production processes and techniques, including irrigation. Irrigation is considered a prerequisite for access to such markets as it is considered important for quality and production regularity. These farmers will be very receptive to any modernization programme that improves the reliability of their production system and that secures their incomes. By grouping with others, they try to maintain maximum levels of added value of their production on the farm storing, sorting, packing and conditioning products as seen in European countries.
Modernization policies should promote such cooperative solutions for groups of farmers based on shared management of equipment.
Modernization of irrigation techniques will always result in production increases and may result in local market price decreases, unless no market organization is anticipated. Cooperative organizations will help farmers become stronger, but some technical assistance is needed to promote such a process. It will result in better production control to adapt to existing markets and in farm income increases, while keeping rural populations in place.
Such cooperative organization allows better irrigation and cropping technology transfer and may contribute to water savings (dissemination of scheduling techniques, deficit irrigation methods). The WUAs can be a first step in achieving this new form of organization. These associations should be designed to initially promote water-oriented cooperative initiatives and then to become multipurpose.
6. Farmers and water conservancy
6.1 Productivity issues for farmers
As mentioned previously farmers are primarily focused on land productivity by trying to maximize the gross profit margin per hectare (Montginoul 2004). They will extend their irrigated surfaces and re-allocate the water saved by the modernization of the distribution system to new plots. Water productivity is not a priority issue, except when water becomes scarce or volumes limited. If the water price increases, water is considered as an input and managed accordingly on the farm. It will be allocated where cost return is the highest. In both cases scheduling methods must be part of the modernization process; water saving may be a secondary achievement.
When farmers develop private pumping they will favour this solution instead of a public network. It is generally more reliable, does not require any anticipation (water shifts) and in some (many?) cases, unauthorized pumping is left unpunished. When water shifts are too long, it is the only way to gain access to modernization, anticipate irrigation scheduling and thus save water.
Private pumping is not considered expensive by the farmer when equipment has already been purchased; direct operating costs (energy) will be regarded as the only cost.
In addition, pumping often provides water of better quality in terms of suspended material, making it easier to filter for micro-irrigation. When salinity increases in water tables, water from the public supply will be used to mitigate salinity.
6.2 Cost effectiveness of modernization
Modernization is generally cost effective during initial years because of production increases for an equivalent amount of water.
For example water productivity has been increased by a factor of 2 in the Doukala management area for different drip-irrigated vegetable crops (Majouj and Akartit 2004; Plate 4) compared to traditional hand moved sprinkler systems subject to leakage, sprinkler ageing, plugged or worn out nozzles, inappropriate spacing, pressure variations and losses due to drift and evaporation.
In olive tree production in the Damascus region, a farmer visited in 2002 has paid back his micro-irrigation system after the first campaign thanks to production increases.
Plate 4. Private pumping for potato production, Doukala, Morocco
As mentioned previously to be cost effective a modernization project must attain a minimum surface scale. Farmers are often reluctant to group with neighbours to operate equipment in common. Nevertheless, the need for heavy equipment and infrastructure in modern agriculture requires a minimum surface area to be cost effective.
For instance, in Northern France, vegetable production (potatoes, beans, spinach) is considered to be cost effective from 100 ha. Farmers group to form CUMAs (Cooperative for Shared Use of Agricultural Machinery) which provide a solid framework for the management of such associations. The CUMA allows the sharing of equipment and infrastructure for seeding, planting, cropping, processing and conditioning of vegetables, and thus decreases its cost per hectare.
Under the same legal framework, there are examples of groups of farmers managing a centre pivot. The principle of the WUA with extended purpose can be applied for such an activity too.
Modernization policies should facilitate cooperative solutions that are cost effective, more equitable and reduce the numbers of smallholders who abandon agriculture.
6.3 Efficiency of farmers' practices
In modernized areas, farmers still use practices inherited from the past. In micro-irrigation they only stop irrigating when water begins to pond. When they see head loss increases they often remove the filter cartridge (Plate 5), fail to replace it when torn, are unaware that some drippers can be cleaned (Plate 6), and when a part of the plot appears dry, they increase total plot application. When performance decreases too much, they simply keep the pipes for improved basin irrigation (Plate 7). After such failure these farmers are very reluctant to modernize their practices and in addition, they discourage their neighbours from switching to other water-saving techniques.
This is widely observed, except in areas where extension services exist. They assure technology transfer, and make transition more feasible. Where no technical support is proposed, the dealer will be the technical reference even if many are honest and do not take advantage of the situation, they may not be competent, especially in recently modernized areas.
On the other hand farmers usually purchase the cheapest equipment, disregarding its performance and durability. They consider that it will always be better than former surface techniques.
Very often small farmers cannot afford to purchase the equipment, even when subsidized. Many dealers wait for the first yield to be paid; such a "service" has a price which has to be paid back somehow. When price competition is very tough, dealers will buy cheaper products. This results in constant changing of brands and models which makes it complicated to find spare parts when they are needed.
Dealers should commit to a minimum service follow-up for provision of spare parts lasting at least five years to keep equipment durability consistent.
Finally, when speaking with farmers in areas under modernization they preferred a step-by-step modernization strategy to allow minds to adapt to the changes involved, instead of a complete overhaul of methods and practices. Farmers appear to be very conservative especially when they do not understand the process whether it be political or technical in nature.
Modernization policies should also promote improvement of traditional methods and practices, instead of a complete system overhaul that will often frighten away poorly educated farmers.
7. Conclusions and recommendations
To be effective, modernization of farm irrigation requires a global approach to the problem. The consequences of any irrigation system modifications on water consumption and on farm economic performance must be properly assessed.
During the planning of the modernization policy, all stakeholders should be involved. In particular, this participatory planning has to reserve a prominent place for farmers on whom the success of the process heavily depends. This involvement could be made through a steering committee which will have to work initially on the definition of the modernization policy framework, and then estimate yearly its consequences for revision purposes.
The points on which the policy steering committee for modernization will have to focus are:
As the modernization process is long and complex, and involves numerous stakeholders, periodic auditing, managed by a policy steering committee for modernization, is necessary. The efficiency of modernization policy must be questioned and analysed using performance indicators to appreciate:
Numerous activities on this subject should be adapted for awareness campaigns and used for regional analysis of irrigation modernization stakes. It is one of the objectives of the Wademed European programme and of the Sirma6 programme supported by the French Government (2003–2007).
AGR. 2003. Suivi des aménagements hydro-agricoles réalisés par le secteur privé avec l'aide financière de l'etat. Etat d'avancement au 30 Septembre 2003.
AND-I, Cemagref. 2006. L'irrigation sur le Bassin Seine Normandie, etat des lieux et perspectives. Expertise report for Parisian Basin Water Authority.
Bouderbala, N. 2004. Institut Vétérinaire HASSAN II, Rabat (Maroc). L'aménagement des grands périmètres irrigués: L'expérience marocaine. Cahier Options Méditérranéennes. Rabat (Maroc), CIHEAM.
Brabben, T. 2001. Affordable irrigation technologies for smallholders in South Africa. Mission report August 2000.
Carmona, G., Le Grusse, Ph., Le Bars, M., Belhouchette, H. & Attonaty, J.M. Construction participative d'un modèle d'aide à la gestion collective de la ressource en eau. Application au cas du Bassin Aveyron-Lère. Paper presented at the symposium "Territoires et enjeux du développement régional", Lyon, 9–11 March 2005.
International Network of Irrigation Testing Laboratories (INITL). 2005. Draft report of sprinkler distribution measurement results collected from 10 laboratories in the world (available from B. Molle).
ISO. 15886-3 irrigation equipment irrigation sprinklers Part 3: Characterizing of distribution and test methods.
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Latiri, R. 2004. Les efforts de modernization de l'agriculture irriguée en Tunisie. Wademed workshop 1, April 2004, Rabat, Morocco.
Le Grusse P. 2001. Du "local" au "global": Les dynamiques agroalimentaires territoriales face au marché mondial. Quels instruments d'aide à la décision pour l'élaboration des stratégies territoriales? Cahier Options Méditerranéenne, Série B, Etudes et recherches, 32.
6 Systèmes Irrigués au Maghreb.
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Molle, F. & Turral, H. 2004. Demand management in a basin perspective: is the potential for water saving overestimated? International Water Demand Management conference, June 2004, Dead Sea, Jordan.
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1. Guidelines for new rural development
The central government's proposal for rural development has received considerable interest nationwide. In particular, experts and government officials have explored innovative ways to adjust measures to local conditions and prepare suitable guidelines. For instance, the land can be divided into three sectors: "Developed", "intermediate" and "undeveloped" areas. Using economic zones as bases for further disaggregation, they can be split into, inter alia, grain, cash crop, forest, prairie and fishery zones. On the basis of topography, classifications can include plains, hills and mountains.
State compartmentalization into three administrative divisions will facilitate the promotion of different policies to support development projects: Primary administrative villages (villages in cities); secondary administrative villages (villages that are merged); and tertiary administrative villages. Tertiary villages are part of the land that will not be urbanized over a relatively long period of time. With the transformation of the old institution into a new system, the adjustment of economic structure and the policy of liberalization, such land will experience a transition in the context of agricultural modernization. As such, the basic characteristics of rural development in China will feature four agricultural "modernizations" and four "transformations".
1.1 Four agricultural modernizations
Modern agriculture will have the following major characteristics: (1) Agricultural production will intensify; (2) the market mechanism will govern agricultural production; (3) science and technology will affect production, processing and marketing of traditional agricultural products through farm mechanization, upgraded water conservancy and automation of associated equipment; (4) urban–rural integration (reduction in disparity between urban and rural areas, narrowing of the division between agricultural and industrial profits and parity in income between farmers and city residents).
1.2 Four agricultural transformations
(1) Agriculture is transformed from purely traditional agricultural production to modern agriculture in which the economy, society and ecology develop in juxtaposition; (2) the rural economy is transformed from a township collective to a diversified economy (including industry); (3) rural society is transformed from the bifurcation of urban and rural areas to a modernized new countryside with coordinated development of urban and rural areas; (4) farmers are transformed from traditional small producers to empowered and artisanal workers.
2. Overall planning of urban and rural areas: General guidelines for rural development
1 Research fellow, Ph.D. Tutor, Development Research Center of the State Council, China.
3. Overall planning of urban and rural areas, the focus of rural development
The main elements will be: Overall planning of urban and rural areas as well as the acceleration of urbanization, information dissemination, industrialization and farmers' enrichment.
With farmers' increase in income, we should also expedite the development of modern agriculture and the adjustment of rural economic structure.
3.1 Establish the state infrastructure mechanism
3.2 Accelerate the development of a rural society
4. Water conservancy in new rural development
The 11th Five-year Plan is a critical period for the creation of a more affluent society and is an important time for rural development; it will also be instrumental in enhancing the construction of water conservancy infrastructure through "democratic management"2 and by "fostering civilization".3
Water-saving infrastructure (WSI) is essential to: (1) Increase capacity for disaster prevention and reduction; (2) promote the development of agricultural production; (3) improve farmers' living conditions; and (4) improve the ecological environment.
Construction of rural WSI to "improve living standards" will introduce new requirements for rural irrigation and drainage projects and water supply projects. "Improving the overall cleanliness of villages" necessitates new techniques for soil and water conservation, developing rural hydroelectric power, water conservancy in pastoral areas and harnessing water resources.
4.1 Water conservancy progress in China
The trend of continuously deviating from on-farm water conservancy has been contained and key projects have made a good start. Obvious results have been achieved in flood prevention and drought relief; losses caused by disasters have been mitigated. Each administrative area pays more attention to research on and the launching of related water conservancy policies.
4.2 Main constraints vis-à-vis water conservancy development
Many farms still lack basic water supply facilities and the safety of supposedly potable water cannot be assured. Farmland irrigation and drainage facilities are weak, which seriously constrains enhanced agricultural productivity. Soil erosion problems, grassland degeneration and water source pollution are prominent and the deterioration of the ecological environment has not been effectively checked.
2 The need for new management approaches to rural water conservancy.
3 The introduction of new technologies and standardized management for rural water conservancy.
4.3 The main tasks for the development of rural water conservancy
Safe drinking water is the most important objective. Other tasks include: Irrigation and drainage facility reconstruction with water saving as the focus; promoting soil conservation and reducing soil erosion, thus increasing the area of basic farmland; developing hydroelectric power; encouraging water conservancy in pastoral areas and irrigating grazing land.
4.4 The basic ideology for farmland water conservancy
There are three concepts to facilitate rural development:
4.5 Policies and measures for the promotion of water conservancy
Multiple factors constrain the development of rural water conservancy in China. Problems are related to knowledge, investment and management. In particular, project construction investment has been low over the long term and there has been an overall decline in recent years. This is because in the current situation, where the comparative benefits of agriculture have changed, farmers' roles have been established and farmers' democratic consciousness is growing. Consequently we can no longer depend on administrative measures only to develop rural water conservancy so we must accelerate the establishment of effective new mechanisms and measures. Specific suggestions are provided hereunder.
4.5.1 New measures for the basic development of farmland water conservancy
There is a need to fine-tune:
With regard to the last measure, grain productivity in China is insufficient. In future, grain production will also be subjected to the "one increase (people) and three reductions (land, water and planting area)" policy. The annual increase of grain yield should increase to 1.8–2.6 percent from 0.9 percent in the past ten years.
This will be very difficult. We must consolidate WSI, disseminate agricultural science and technology and improve comprehensive agricultural productivity to a new level in order to guarantee grain safety. Currently for the construction of WSI, increasing investment is the major bottleneck. According to expert estimations, the annual cost of maintaining existing water conservancy facilities for farmland nationwide amounts to approximately 240 billion yuan. To realize further development, several trillion yuan will be needed but only 22 billion yuan is available. The state should address this issue and establish a diversified input system with the state playing the major role and the active participation of farmers. Rural water conservancy for farmland, reconstruction of large- and medium-scale irrigation areas and the development of large-scale commercial grain bases are key factors at the moment.
4.5.2 Responsibilities and rights and rethinking farmers' labour contribution
WSI serves "weak" agriculture; it is also the basis for ensuring grain safety and so has very strong societal interest. In this context it should be the major objective for state financing and investment should mainly come from the state. This is the case for developed countries (e.g. United States and Japan) and upper bracket developing countries (e.g. India and Turkey). Infrastructural water supply has a certain commercial quality, so farm households who benefit from it should assume certain responsibilities for maintenance after the completion of projects and during the construction of small projects. With state funding, we should adopt operation by local people but subsidization by the state. Farmers should undertake the construction of tertiary canals and field distributions and be involved in small water conservancy projects. We should formulate detailed rules for farmers' labour contribution. Different government levels should be responsible for the funding of farmland water conservancy. Now that township level financing has been removed, county level financing has been experiencing widespread difficulty. So the central government and provinces (autonomous regions) should assume more responsibilities. As state financing is not bottomless, we should encourage farmers to contribute their labour for water conservancy activities.
4.5.3 Accelerate reform on water infrastructure investment and management modes
Currently multiple departments participate in the development of water infrastructure for agriculture. However integrated planning is absent, subsidies are not uniform and the abundance of many players in one programme discourages investment in and the uniform management of water resources and projects. The state should further define the responsibilities of every department and underscore the uniform management of water conservancy technology by one department. We should accelerate reform on water infrastructure investment and management modes. In this context, WUAs can play an active role in mobilizing farmers' enthusiasm and empowering them.
Developing water conservancy projects for agriculture is not straightforward and requires strong supporting policy. In particular, owing to the rapid development of industrialization, urbanization and modernization, government leadership needs to be stiffened. Enhancing comprehensive agricultural productivity is not easy; it requires further inputs and government funding, farmers' enthusiasm and manifold construction of appropriate infrastructure.
4.5.4 Substantially increase government investment in rural water conservancy
In the past, building relevant infrastructure in China, in particular, small schemes, mainly relied on farmers. The thinking has been that "farmers should handle their own affairs". Problems included: Low construction standards, no subsequent maintenance and no exploitation of benefits. To adapt to the new rural development trend, we must find new solutions to addressing rural water conservancy inputs based on local characteristics and governmental responsibilities. Government assistance should be increased substantially and a diversified input mechanism with government investment taking the lead should be established with voluntary inputs from farmers as the foundation and auxiliary social inputs as supplements.
Firstly, the scale of central financing should be boosted. In 2005, central financing's special fund for small-scale water conservancy development was 0.3 billion yuan; in 2006 this climbed to 0.6 billion yuan. We suggest that the 2006 subsidy should be increased to three billion yuan in 2007 and by further increments year by year. Each province should also increase the scale of financial subsidies. Secondly, we should adjust the investment structure of the state's comprehensive agricultural development funding system and increase the investment proportion for key projects in medium-scale irrigation areas. At present, such investment is approximately 0.15 billion yuan every year. At this rate we will need 70 years to complete tasks related to key projects. We suggest that the amount be increased to one billion yuan every year. Thirdly, we should increase similar investment for key projects in large-scale irrigation areas. In recent years, the central government has set aside 1.5 billion yuan annually for this, which can only support a small number of projects and mitigate hazards that are present. Meanwhile annual investment remains very unstable. According to the current level, it will take 30 to 40 years to complete the reconstruction of key projects. We suggest that in this case investment should be increased to 3 billion yuan.
4.5.5 Highlight the uniform planning of rural water conservancy in counties
We should arrange for uniform planning of WSI under the leadership of county governments; they will be guided by water conservancy departments, with related departments participating. After planning has been completed, it should be approved by higher authorities. Such planning, after approval, will apply to the whole county, not single departments or units. All related departments and units should strictly implement the agenda with no interruptions or changes. Through planning, we can better understand conditions, standardize outputs, provide coordination, integrate investment and improve efficiency with regard to deployment of funds.
4.5.6 Formulate and launch early regulations on rural water conservancy
We suggest that a state law on "Rural Water Conservancy" be formulated; inter alia, this will stipulate investment, construction and management mechanisms and operational modes for rural water conservancy as well as responsibilities for different governmental and departmental levels. As launching this law at present is difficult, we advocate initial research first to formulate "Regulations on Rural Water Conservancy".
4.5.7 Indices for rural water conservancy infrastructure
WSI is implemented to ensure enhanced farmers' income, improvement in living standards and development of production. Farmers must be guided by various indices. As geographic conditions, economic development and human factors differ from place to place, we should formulate evaluation indices according to local realities and should not make uniform requirements. The author suggests that evaluation indices address aspects related to infrastructure investment and living standards. We should evaluate infrastructure investment through seven indices: (1) The average annual sedimentation rate of ditches and ponds in a village is lower than 1.5 percent; (2) the execution of ancillary structures on fields per mu is over 65 percent; (3) the proportion of losses generated by floods and drought in the GDP is less than 2.5 percent and the average loss rate per mu is lower than 3.5 percent; (4) the use of tap water is over 90 percent; (5) the quality of ecological water is over 70 percent and surface water quality exceeds Class III; (6) the standardized discharge of sewage is over 50 percent; (7) the average input into WSI per capita is no lower than 200 yuan.
Living standards are evaluated through four indices: (1) Water surface area per capita is greater than 8.6 m2; (2) water resources per capita are no lower than 600 m3; (3) household water per capita is 80–120 litres/day and the quality is 100 percent; (4) ambient air quality exceeds grade 11.
The development of WSI is an important programme for national progress, affording peace and security and constructing a harmonized society. It is the foundation for agricultural and rural development. We should not forget major disasters and subsequent problems that emerged; view water conservancy development from the overall socio-economic perspective; fully understand the importance, protracted nature and difficulties involved in constructing such infrastructure today; protect, guide and generate enthusiasm among farmers; and inculcate each tier of society to strengthen and promote this programme nationwide.
As elsewhere in the world, Australia's irrigation systems suffer from problems associated with losses in storage and conveyance, on-farm losses and variable water use efficiency. In the Murray–Darling Basin (MDB) it is widely accepted that 25 percent of diversions for irrigation is lost during conveyance in rivers, 15 percent is lost from canals and 24 percent is lost on farm, meaning that only 36 percent of irrigation water is actually delivered to plants. Such losses are not atypical across the world (Table 1). The data in Table 1 for the Murrumbidgee Irrigation Area (MIA) do not include river conveyance losses and indicate on-farm losses better than the overall MDB average (Khan et al. 2004). However, given that the world will need to feed 1.5 to 2 billion extra people by 2025, there has to be scope to reduce water conveyance losses and irrigation efficiency both in Australia and internationally.
Table 1. Surface water irrigation efficiency in three irrigation systems
|Key indicators||Liuyuankou China||Rechna Doab Pakistan||MIA Australia|
|Area (ha)||40 724||2 970 000||156 605|
|Losses from supply system (%)||35||41||12|
|Field losses (%)||18||15||11|
|Net surface water available to crop (%)||46||32||77|
In recent years, there has been a growing concern in Australia regarding the impact that major diversions of water for irrigation are having on the environment. This is creating further "economic" competition for water along with demands from urban and industrial users. Given that rural water users (predominantly in the irrigation domain) account for over 70 percent of Australia's total water use, a figure similar to that in most Southeast Asian countries, and given increasing physical scarcity of the resource owing to climate change and other environmental factors it is not surprising that pressure is increasing on irrigators to increase water use efficiency and to achieve "true water savings" by conserving water otherwise lost through non-beneficial evaporation or seepage to saline aquifers.
The key to achieving "real" and substantial water savings lies in the technical, economic and institutional assessment of water-saving options in a "whole of the system" context.
Figure 1 shows the water cycle in an irrigated catchment at different spatial scales. Key interventions for improving the sustainability of irrigation systems and achieving water savings are indicated by numbers in circles. These interventions are described hereunder:
1 Charles Sturt University and CSIRO Land and Water, School of Science and Technology, Locked Bag 588, Wagga Wagga, NSW 2678, Australia. E-mail: Shahbaz.email@example.com
This paper describes the technical, economic and institutional aspects of water use efficiency studies focusing on interventions 1 to 5 for catchments in Australia. Modelling approaches aimed at extrapolating the impact of water savings on basin and country level food security and water balance are provided by Khan et al. (2005c, d).
Figure 1. Schematic of irrigated catchments with key interventions (in circles)
2. Technical issues
It is imperative to save water to achieve higher productivity per unit of water consumed and to provide water for the environment. However lower commodity prices do not allow investment in higher technologies owing to government subsidies and international market competition.
Technical options for more efficient use of available water supply for irrigation include:
The relative economic and environmental merits of adopting these alternative water-saving options on overall water saving and water productivity at the irrigation system or catchment level are largely unknown due to a lack of integration of existing data sets. Therefore it is imperative to start identifying and filling in vital gaps. As a part of the Pratt Water Study (Pratt Water 2005) in the Murrumbidgee catchment, a targeted data-gathering, modelling and integration approach (Khan et al. 2005a, b) was adopted to evaluate alternative technologies for reducing over 300 GL (1 GL = 1 million m3) on-farm and off-farm losses within the Coleambally and the Murrumbidgee irrigation areas.
2.1 System approach
2.1.1 Water-saving options at the catchment level
To identify "true" water-saving options it is important to adopt a system approach for accounting for all surface water and groundwater use, losses and interactions at the catchment, irrigation area and farm levels. An example of a system's water balance for the Murrumbidgee catchment level is shown in Figure 2.
Figure 2. System's water balance at the Murrumbidgee catchment level
This analysis has shown unaccounted losses of greater than 300 GL in some of the river reaches (Khan et al. 2004b) which could lead to real water savings and better environmental management by investments in catchment management infrastructure.
2.1.2 Water-saving options at the irrigation area level
A similar system's approach at the irrigation area level provides indications of water savings at the whole of the irrigation area level. An irrigation system's water balance for the Coleambally Irrigation Area (CIA) is given in Figure 3 which provides a possible water use efficiency scenario for the CIA (using 2000–2001 water allocations). The water use efficiency at various points within the system is expressed in terms of water delivered versus the water supplied and net water use through evapotranspiration and the tonnes/GL of produce. Key water use efficiency indicators for the CIA show that irrigation efficiency in terms of root zone storage to the water diverted from the source is 70 percent. Unless there is an investment in irrigation infrastructure to improve measuring, monitoring and reduction of losses this efficiency indicator will remain low. The overall water use efficiency of the CIA is 77 percent due to capillary water use by the crops. In terms of production efficiency the CIA is at 343 tonnes/GL. Further analysis of the whole of the CIA water savings shows (Khan et al. 2004b) that it is possible to increase economic water use efficiency from US$91 000/GL to 97 500/GL and total water use efficiency from 77 percent to 84 percent under the current cropping and irrigation regimes.
Figure 3. Base case water use efficiency of the CIA
2.2 Targeted water savings
2.2.1 Increasing on-farm water productivity
Table 2 provides an overview of the net crop water requirements (NCWR), current irrigation levels and yields in the MIA. In all cases (except for alfalfa) NCWR are well below the maximum reported irrigation application levels. There are major differences between minimum and maximum crop yields, as well as the overall amount of water consumed and the NCWR. These data clearly illustrate that there is a potential to increase farm profitability at a range of levels which include:
Considering a range of soil, water and groundwater conditions, Khan et al. (2004a) concluded that on-farm irrigation technology conversions can provide potential water savings ranging from 0.1 to 2.2 ML/ha for different broad acre crops (Figure 3); for example, 1 to 2 ML/ha from flood to sprinkler and 2 to 3 ML/ha
Table 2. NCWR, reported water use and yields in the MIA (2000/2001 reported crop areas are used)
|Crop||Crop area (ha)||NCWR||Reported irrigation (ML/ha)||Reported yield (MT/ha)|
|Rice||46 120||506 562||11||14||12||16||9.5||6||12|
|Wheat||39 215||111 835||2.9||2||1||3||5||3||7|
|Oats||2 896||7 512||2.6||2||1||3||3.5||2||6|
|Barley||3 034||8 615||2.8||2||1||3||5||2.5||7|
|Maize||2 924||18 813||6.4||8.5||6||12||9.5||6||15|
|Canola||2 685||4 643||1.7||2.5||1||4||2.5||1.8||3|
|Soybean||2 881||18 383||6.4||8||6||9||2.6||1.5||3.8|
|Summer pasture||3 929||45 154||11.5||7.5||7.5||8|
|Winter pasture||24 184||50 403||2.1||5.5||5.5||6|
|Alfalfa (uncut)||2 468||43 291||17.5||10||7||14||7.3||5||15|
|Vines||13 635||77 508||5.7||5||3||7.5||15||9||25|
|Citrus||8 700||68 861||7.9||7||4.5||10||38||20||60|
|Stone fruit||934||9 071||9.7||9||7.5||12||18||15||20|
|Winter veg.*||1 500||921||0.6||5||4||6||60||50||70|
|Summer veg.**||1 500||8 906||5.9||7||6||10||90||60||120|
|Total||156 605||980 477|
Reported irrigations levels are subject to adjustment for measurement error, e.g. 14 percent accepted underestimation by the Dethridge wheels.
* The irrigation requirement and yield is for onion. For salad crops (lettuce), the irrigation requirement is 2–4 and yield is 30–40.
** The irrigation requirement and yield are for tomato. For melons, the irrigation requirement is 4–7 and yield is 30–40.
Reported gross diversions for 2000/2001 are 1 048 000 ML and on-farm deliveries are 857 000 ML.
Sources: Hope and Wright (2003); Beecher (1995); MDBC (1997); MIA & DLWMP WG (1997).
from flood to drip irrigation for citrus; 1 to 1.5 ML/ha from flood to sprinkler and up to 4 ML/ha from flood to drip irrigation for vineyards and 0.5 to 1 ML/ha for vegetables. Modelling simulations show water-saving potential of 7 percent for maize, 15 percent for soybean, 17 percent for wheat, 35 percent for barley, 17 percent for sunflower and 38 percent for broad bean, if on-farm surface irrigation methods can be replaced with pressurized irrigation systems.
Based on recent work by Khan et al. (2004a) the potential savings for converting from good surface water to pressurized irrigation systems (travelling irrigators or centre pivots or equivalent) are shown in Table 3.
Table 3. Water use and savings (ML/ha) for selected crops under different irrigation technologies
|Irri. method ML/ha||Surface||Sprinkler||Water savings|
2.2.2 Measuring and managing water losses from supply channels
The study used a combination of geophysics and in situ measurement methods aimed at identifying seepage hot spots and the extent of overall water losses. In the Murrumbidgee catchment seepage measurements were made over 700 km of channels. Both sides of the selected channels were surveyed using EM31 meters. These meters use electromagnetic induction to measure the average electrical conductivity of the soil from the surface to a depth of 6 m. This average reading is known as "apparent conductivity". The EM method provides a quick way of gathering many data without any ground intrusion but is susceptible to interference from electrical or magnetic interference. Low conductivities indicate potential seepage sites.
Once the EM31 surveys were completed, maps were prepared from the EM imaging data using GPS-based locations. These maps helped to identify the parts of channels where higher seepage rates were occurring. Doppler flow meters were then used to measure inflow and outflow of hot spot reaches of channels to cross-validate losses from channels. At the high seepage sites, Idaho seepage meters were used to quantify seepage rates. In this method a cylindrical bell is pushed into the bottom side of a channel and is connected by tubing to a reservoir and gauge located on the water surface. As water seeps from the bell, the change in pressure in the reservoir is measured by the gauge.
EM31, Idaho seepage meter and groundwater lithology and quality data from a MODFLOW model were used to "train" an artificial neural network (ANN) model (Khan et al. 2004b). Once trained, the network can be used for predicting seepage rates in channels.
Study of on-farm conveyance losses on nine farms showed that seepage losses vary from 1 to 4 percent of the total water supplied which can be more than 60 ML/year (equivalent to 4 percent loss) for a studied farm.
Seepage losses computed for over 700 km of channels in the MIA showed that seepage losses were over 40 000 ML/year and evaporation losses were over 12 500 ML/year. The total losses in given channel reaches vary widely and can be from 1 to 30 percent of the water supplies and 0.2 to 9 percent per kilometre length.
Canal lining and piping options were considered for saving conveyance losses from channels.
2.2.3 Ladder of water savings
Possible on- and off-farm water savings can be summarized as steps of a ladder of increasing on-farm and off-farm water savings (Figure 4) and water benefits. It is important to recognize that some steps are prerequisite for the next water use efficiency level. For example, to realize on-farm water savings it is crucial to implement soil and groundwater and flow monitoring programmes, to ensure irrigation levels are being matched with the crop water requirement, at the same time considering conversion to sophisticated irrigation. Similarly, for realizing off-farm water-saving options, it is vital to know how much water is being delivered in space and time before piping/lining of channels. It is important to reduce the conveyance difference and narrow the wide gap between the gross diversions from rivers to deliveries on farm by installing state-of-the-art monitoring and delivery systems as a part of the modern irrigation infrastructure.
3. Economic issues
To target on-farm and regional water savings it is hypothesized that the marginal costs for saving irrigation water will increase with the volume of water saved and there is a possibility to formulate irrigation water-saving cost curves for traditional or alternative different irrigation technologies to help shift these cost curves to lower costs as illustrated in Figure 5. Figure 5 shows a simplified schematic of the marginal costs (MC) and benefits (MB) for the current cropping systems. X represents the current viable levels of water savings which can be shifted to the right through the low cost alternative technology.
Figure 6 shows capital investment and total water savings by sophisticated irrigation technologies in the MIA. Typical capital costs to save one ML of water vary from less than US$2 000/ML to over US$7 000/ML depending upon soil type, crop and irrigation technologies used.
Figure 4. Ladder of possible water savings in an irrigation area
Figure 5. Cost–benefit curves for water-saving technologies
Figure 6. Capital investment and total water savings by sophisticated irrigation technologies in the MIA
Break-even analysis (not presented here) shows that the break-even years for conversion from flood to the pressurized irrigation systems are too long (greater than 15 years). There is a need to reduce the break-even period by considering leasing of water for the environment from farmers at around US$300/ML for a fixed period of five to ten years after which the water can be returned back to the farmer and the government can then lease the next lot of water from another group of farmers. This will help remove barriers to the adoption of irrigation technologies by moving farmers and irrigation areas to the next step of the irrigation efficiency ladder, reducing local and regional environmental impacts and securing water for better ecological futures.
The economic analysis of alternative water-saving technologies for channels showed that the cost of saving one ML of water increases with the total savings, as shown in Figure 7. Typical capital costs to save one ML of water vary from less than US$500/ML to over US$4 000/ML depending upon losses per unit length and the seepage reduction method used.
In Australia there is wide feeling that water savings which cost more than US$1 000/ML are not viable. The break-even analysis of different channel lining materials by Khan et al. 2004a shows that the price of saved water on an annual basis needs to be from US$30 to over US$200 to break even within the design life of the project. This investment can be achieved in two ways, by either using the saved water on higher value crops or by including saving costs as part of the overall water supply charges with a proportionate cost-sharing arrangement. For example, water delivery charges will increase by 5 to US$15/ML/season to provide water more efficiently. This will also reduce waterlogging and salinity abatement costs (current estimate for waterlogging and salinity abatement are US$10 to US$200/ML or recharge/year). The proportional cost to be paid by the farmer may be less than discussed here if it can be shared with the wider environmental beneficiaries. There is a need to promote a water efficient culture through "preferential rights of access" by providing a better level of security to farmers and irrigation companies investing in water-saving technologies.
Figure 7. Capital investment curves for saving seepage losses
4. Institutional issues
4.1 Who saves and who owns the water losses?
One of the key impediments to achieving real water savings is the issue of ownership of losses and how to re-allocate on- and off-farm water savings. In New South Wales, conveyance losses are collectively "owned" by the farmers via privatized irrigation companies through a conveyance allowance. For example there is a provision in the Murrumbidgee Water Sharing Plan (Department of Land and Water Conservation 2003) for a conveyance access component for the Murrumbidgee Irrigation Company of up to 243 000 ML to make up for the transmission loss in water accounting (Clauses 26 and 40). Similarly farmers are given water entitlements irrespective of the actual crop water use. This water entitlement is used to irrigate crops which results in evaporation and deep percolation losses. If farmers invest in new technologies to save water losses they may like to increase their area of production or sell the saved water on the open market.
Institutional complications are caused by the common pool nature of the irrigation supply infrastructure and deep drainage below the root zone. This may lead to lack of collective action. Managing irrigation systems requires coordination among many users sharing the same resources of water and irrigation infrastructure. Users receiving the direct benefit are likely to ignore the effect of their actions on the common pool when pursuing their self-interest, therefore the environmental sustainability of surface and groundwater resources and maintenance of irrigation infrastructure risk a "tragedy of the commons".
To explore reasons for the lack of action by farmers and irrigation companies, reference can be made to the long break-even years (greater than 15 years) to achieve net profit from investment for conversion from flood to pressurized irrigation systems in the case of the Murrumbidgee Catchment. Farmers also have a lack of interest to permanently give up their water entitlements in exchange for capital incentives for new technology owing to uncertainty arising from current and proposed water reforms.
A business case for achieving water savings at the farm, regional and basin level has already been established by the Pratt Water Feasibility Study in the Murrumbidgee Catchment which asks for a uniform national water efficiency and environmental regulatory framework using the Council of Australian Governments (CoAG) framework (Pratt Water Group 2005).
Recently the Australian Government has initiated a National Water Commission (NWC) to drive the reforms more quickly. At the water distribution and on-farm level, the focus of reform and research is on:
However, there are still major differences in productivity across farms, so considerably more effort is also required to identify the biophysical, management practice and social reasons behind this variability in order for all enterprises to work more productively.
5. Conclusions and way forward
In order to achieve true water savings, a system approach is necessary to target "real water savings" and to remove technical, economic and institutional barriers.
A system approach adopted in the Murrumbidgee Catchment showed accounted losses of greater than 300 GL can be saved (Khan et al. 2004a, b). The on- and off-farm water-saving costs vary from less than US$50/ML to well over US$5 000/ML. Such investments can be possible either by using the saved water on higher value crops or by including saving costs as part of the overall water supply charges with a proportionate cost-sharing arrangement. There is a need to reduce the break-even period by considering "leasing of water" for the environment from farmers at around US$300/ML for a fixed period of five to ten years after which the water can be returned back to the "owner" and the government can then lease the next lot of water from another group of farmers.
If the water saving technologies are considered on their own, costs involved will be prohibitive to result in any substantial investments by the individual farmers and irrigation companies. This is mainly because irrigation supply systems represent a shared and jointly owned common pool resource. There is the possibility of inaction among local, regional and national actors leading to market failure and a classic tragedy of commons. Institutional reforms aimed at minimizing risk of market failure driven by the tragedy of commons are required to secure a win–win situation for all stakeholders.
Due to lower commodity prices, farmers and irrigation companies on their own will be unable to achieve water savings. Unless water-saving costs and benefits are shared by all players in a catchment, "real water savings" are not possible. Private–public investment models aimed at providing "preferential access rights" to those who save water by investing in water-saving technologies may be one of the possible ways forward.
Data inputs from the Department of Land and Water Conservation, NSW Department of Primary Industries and Irrigation Companies are acknowledged. Funding support from ACIAR, the Pratt Water Group and CSIRO's Water for a Healthy Country flagship programme is appreciated.
Beecher, G., McLeod, G.D., Pritchard, K.E. & Russell, K. 1995. Benchmarks and best management practices for irrigated cropping industries in the southern Murray-Darling Basin, NRMS I 5045. Final report.
Department of Land and Water Conservation. 2003. Water sharing plan for the Murrumbidgee regulated river water source. 2003 Order.
Hope, M. & Wright, M. 2003. Murrumbidgee Catchment irrigation profile. Written and compiled by Meredith Hope and Marcus Wright. NSW Department of Agriculture.
Khan, S., Rana, T. & Blackwell, J. 2004. Can irrigation be sustainable? Proceedings of the 4th International Crop Science Conference. Brisbane New Directions for a Diverse Planet: 4th International Crop Science Conference. 26 September to 1 October 2004. http://www.regional.org.au/au/cs/2004/symposia/1/7/1399_shahbazkhan.htm
Khan, S., Akbar, S., Rana, T., Abbas, A., Robinson, D., Paydar, Z., Dassanayke, D., Hirsi, I., Blackwell, J., Xevi, E. & Carmichael, A. 2005a. Off- and on-farm savings of irrigation water. Murrumbidgee valley water efficiency feasibility project. Water for a Healthy Country flagship report. Canberra, CSIRO, 16 pp. http://www.cmis.csiro.au/healthycountry/reports/Water_savings_low.pdf
Khan, S., Rana, T., Beddek, R., Blackwell, J., Paydar, Z. & Carroll, J. 2005b. Whole-of-catchment water and salt balance. Identifying potential water saving and management options in the Murrumbidgee Catchment. Water for a Healthy Country report. Canberra, CSIRO. 16 pp. http://www.cmis.csiro.au/healthycountry/reports/Salt_balance_low.pdf
Khan, S., Mu, J., Hu, Y., Rana, T. & Zhanyi, G. 2005c. Systems approaches to achieve real water savings in Australia and China. 19th International Congress on Irrigation and Drainage, 10–18 September 2005, Beijing China. ISBN 81-85068-96-8.
Khan, S., Mu, J., Jamnani, M.A, Hafeez, M. & Zhanyi, G. 2005d. Modeling country water futures using food security and environmental sustainability approaches. 16th Congress of the Modelling and Simulation Society of Australia and New Zealand, 12–15 December 2005. CD proceedings.
MIA & Districts Land and Water Management Plan Working Group. 1997. MIA & Districts Land and Water Management Plan, Griffith.
Murray–Darling Basin Commission (MDBC). 1997. Inland agriculture, best management practices and benchmarking study. Inland Agriculture Pty. Ltd., in association with Hutchins Agronomic Services, Darlington Point.
Pratt Water Group. 2005. The business of saving water. Report of the Murrumbidgee Valley Water Efficiency Feasibility Project. Report prepared under the Pratt Water Murrumbidgee Project a collaborative venture funded jointly by the NSW and Commonwealth governments under the National Action Plan for Salinity & Water Quality, and by Pratt Water Ltd.
1. Water management
After the Second World War, natural resource exploitation increased significantly due to growing populations, industrialization and urbanization. This has subsequently compromised economic gains. Natural resources currently face huge pressure and many are almost exhausted with concomitant threats to livelihoods. Although natural water supplies are limited, demand continues to increase. Thus there is a need for sustainable regional development through careful management of water resources and monitoring of their relations with society and the physical environment.
1.1 Water resource use
Water is critical for maintaining all forms of life and supporting agricultural and industrial production. Its circulation method the hydrological cycle can be affected adversely by human activity.
Water has natural and social benefits so water resource management must take natural laws into account. Water use can be bifurcated into consumption and non-consumption modes. The main consumers are human settlements, agriculture and industry although they can contribute to restoring water balances. But water volumes have decreased and water quality has changed due to disruption of integrated ecological factors. If one is affected, the others will suffer as well, influencing the whole ecosystem. If water resources are depleted, lakes and rivers will shrink, desertification will occur and ground subsidence will result.
1.2 Water demand
Population rise and economic development exacerbate water demand. When average water availability per capita and natural water supply are low, sound demand management is the only option for sustainable regional development. The basic policies for demand management include: Restricting industrial production to conform with available water supply, the creation of a water-saving society, adjusting the water-pricing system, suppressing water demand and increasing sectoral water use efficiency.
1.3 Water resource systems
In the context of development and utilization, water resource projects comprise infrastructure and technical management units, which are interconnected. They address ecosystem and socio-economic management. Natural and artificial approaches can be used in combination to achieve desired results. With increasing water exploitation, artificial approaches have become more comprehensive in scale, structure and function.
2. Concepts for water resource allocation
2.1 Water resource allocation
How to allot water resources to meet societal and economic demand and avoid damage to ecosystems is a major issue, which supposedly can be resolved by rational allocation of supplies.
Such allocation should include: Equitable, efficient and sustainable principles; the use of mechanical or natural control measures, reasonable suppression of demand, guaranteed supply, environmental protection, temporal and spatial distribution of supplies among water use departments and promoting sustainable regional development. The substance of allocation is to deal reasonably with water competition among all users and to improve water use efficiency.
1 Professor, Hehai University, No.1 Xi Kang Road, Nanjing City 210098, China.
Various factors need to be considered for development practices:
(1) With respect to sustainable development, harmonize human and environmental co-existence.
For socio-economic development, water resources have to be utilized for human welfare but this can be juxtaposed by maintaining short- and long-term environmental balances. In this context, equitable allocation needs to be analysed with care.
(2) With respect to socio-economic development, consider equitable allocation and economic benefits.
Water resources must be utilized fairly to ensure social harmony. Therefore, when allocating water resources, equity and benefits must be simultaneously balanced to promote development.
(3) With respect to water resource development and utilization, supply and demand for water resources must be regulated.
A model for water resource development, utilization, protection and management needs to be researched; introduced technologies should be feasible, economical and environmentally safe. For water demand, ecological and industrial (structure and productivity) issues should be addressed, efficient water-saving technologies should be disseminated, increased water demand should be suppressed and adverse conditions should be accommodated. Regarding regular water supply, competition among water users should be coordinated, rainfall and groundwater should be subjected to careful husbandry and passive attitudes towards water distribution should be changed.
2.2 Models for water allocation
2.2.1 "Demand determines supply" model
This model is based on the concept that water resources are inexhaustible. According to predicted water demand on economic scales, water supply projects should be planned taking careful consideration of water requirements and avoidance of exploitation by overambitious schemes that interfere with river flow or incur desertification, ground subsidence and saline intrusion. If there is no water-saving awareness, application and dissemination of water-saving technologies will be difficult, generating waste and conflict between supply and demand.
2.2.2 "Supply determines demand" model
This model arranges productivity planning according to available water supply and industry structuring according to resource wealth; this is beneficial for protecting water resources. Water resource development is closely associated with regional economic development. For example, economic development enhances investment in water resources and the application of advanced technologies. Possible supply volume is also connected with economic development but exact volume is difficult to determine, so it is difficult to create a model for the development of regional economy in this respect.
2.2.3 Water allocation based on macroeconomy
The aforementioned models stress either supply or demand, isolate water resource demand from supply and neglect the dynamic coordination between water resources and the regional economy. Consequently the allocation theory for water resources, based on macroeconomy, is useful. It involves development of regional economy and a dynamic balance between demand and supply.
The relationship between water resource systems and the macroeconomy system is symbiotic. When water requirements grow because of regional economic development, the demand for water supply correspondingly increases rapidly and investment in water management infrastructure should be furthered. Hence, different sectors have to adapt to the degree and difficulty of water resource development. By analysing inputs and outputs, the water resource allocation theory takes account of the macroeconomy in order to realize coordinated development between regional growth and resource utilization. However it does not dovetail with sustainable development as regional growth may incur environmental pollution or potential ecological damage.
2.2.4 Sustainable development and water allocation
The main objective of water allocation is to balance resource, economic and ecological components. Sustainable water allocation adopts the strategy of coordinated development among the population, resources, environment and economy. While protecting the environment (including the water environment), it promotes economic and thus societal prosperity.
Sustainable development is an ideal model for water allocation, but needs further analysis.
2.3 Measures for water resource allocation
2.3.1 Engineering control measures
These measures involve rational storage, transfer and allocation of water resources. Temporal allocation addresses reservoirs, lakes and underground storage; spatial allocation addresses conveyance, river diversion works, canals, tubewells and pumping stations; quality regulation addresses: Clean tap water, polluted water treatment and desalination.
2.3.2 Economic measures
Establish a distribution and transfer model for rational water rights and rational water pricing, using economic factors, market allocation, preference for high efficiency water use areas and improved water use efficiency.
2.3.3 Legal and managerial measures
Allocation of water resources to water users via legal and managerial instruments.
2.3.4 Scientific and technological measures
Establish real time monitoring systems, scientifically analyse water demand, strengthen demand management, finalize decision-making, improve modernization of water resource regulation and rationally allocate water resources.
2.4 Water resource carrying capacity
As a result of the rapid economic development of industrialized countries, environmental pollution and resource shortages have become increasingly prominent; concomitantly, water utilization and demand have also risen sharply. From 1940 to 2000, freshwater extraction from rivers, lakes, reservoirs, groundwater and other water resources has increased fourfold. Unfortunately, many waterbodies and underground sources are severely polluted. Freshwater supply has diminished considerably. In many regions worldwide, freshwater pressure is becoming more and more intense and in some areas it is unavailable.
3. Scientific methods for rational water resource allotment
3.1 Sustainable development
Under the premise of protecting the environment, can the global economy keep growing sustainably? This is the issue of sustainable development. On the path to sustainable development, humankind has paid very high costs. There have been several representative stages:
1962: Rachel Carlson's silent spring pondered how humans and nature can exist in harmony.
1972: The Club of Rome and the limits to growth postulated that without change in development models, sooner or later we will face development constraints.
1978: The Report of the Brundtland Commission, our common future, first proposed the concept of sustainable development.
1992: The United Nations Conference on Environment and Development and the Rio Declaration expanded the concept of sustainable development into a global strategy.
3.2 Engineering control measures for water resource systems
Modern water resource systems are generally: (1) Large scale; (2) multifunctional; (3) complex in structure. Therefore, systematic concepts and approaches should be used when analysing and resolving water resource issues.
A few key points are:
(1) Risk. Generally, decision-making looks to the future and predictions are not always accurate. There is a need to estimate decision-making risk.
(2) Multipurpose decision-making is often competitive; how can decision-making objectives be balanced?
(3) Scale. Decision-making is affected by differences in regions, cultural backgrounds and local people's benefits. Understanding this is important for effective coordination and implementation of water resource systems. Resolving issues needs to be done thoroughly and not in a piecemeal fashion.
3.3 Application of modern information technology
Do more to disseminate 3S (RS, GIS and GPS) technology, information transfer technology and decision-making support systems; comprehensively develop and adopt technology for water resource management and provide appropriate decision-making tools.
Shanxi Province experiences severe water shortages and the shortage trend has increased in recent years. With rapid socio-economic development in Shanxi, conflicts generated by water shortages are becoming more intense. There is an urgent need to: (1) Address exploitation for livelihoods and production by harnessing the Yellow River, surface and groundwater sources in order to realize their conjunctive use; and (2) form a new pattern of water resource utilization to meet socio-economic development demands. By doing so, the ecology of the water environment will improve.
There are a number of key characteristics concerning water resource allocation in Shanxi:
(1) Total water reserves are insufficient and temporal and spatial distribution is uneven; rainfall and floodwater inputs should be harnessed. Average annual precipitation in Shanxi is approximately 483 mm only and the average total volume of water resources annually is ±12.38 billion m3. Average water availability per capita is 381 m3, about one-seventh of the national average and considerably less than the worldwide average. Average water availability per hectare of cultivated land is 180 m3, about one-tenth of the national average and much less than the worldwide average. Around 60 percent of the total annual precipitation is concentrated in July and August. Infrastructure capacity to harness rain and floodwater resources should be strengthened.
(2) Groundwater is severely overexploited and the ecological environment has deteriorated; groundwater overexploitation must be controlled and the ecological environment must be protected. Overexploited groundwater areas, centred around cities, approximate 10 600 km2 and the overexploited water volume is about 0.7 billion m3. Groundwater levels in Taiyuan City have dropped to 100 m and karst water levels annually drop by about 2 m.
(3) Water from the Yellow River can be used to efficiently increase regional water supply. Annual diversion flow is 1.2 billion m3 for the Shanxi Wanjiazhai Water Complex on the Yellow River. Annual polluted water discharge is about 1 billion m3. Coal mining does major damage to water resources.
(4) Disseminating water-saving technologies will improve water use efficiency.
Based on the Berlin Principle (good scientific practice), water resource management means: Without damaging the sustainability of important ecosystems, promote the coordinated development and utilization of water, soil and related resources to optimize socio-economic progress. In this regard, the following aspects are important:
(1) Humans and the environment can co-exist in harmony; water resources should promote economic development and the ecological environment should be protected and nurtured.
(2) Comprehensively consider and treat flooding, water shortage and water pollution problems.
(3) Examine engineering and natural options for developing infrastructure; build a water-saving society.
(4) Explore and apply theories on water rights, water prices and water markets, by means of government and market regulation models.
Guided by sustainable development, system theories, new technologies and rational water allocation, improve utilization efficiency and ensure sustainable regional development.
The Islamic Republic of Iran is located in one of the most arid regions of the world. Agriculture is one of the most important economic sectors accounting for 18 percent of the GDP and 25, 85, 25 and 90 percent of employment, food supply, non-oil products and raw materials used in industry respectively.
Aridity and drought are common nationwide. About 64.7 percent (105 million ha) of the country's total area experiences arid and semi-arid climates. Average annual precipitation is 250 mm and varies both spatially and temporally. The north, west and southwest regions cover only 30 percent of the country's total area but receive approximately 56 percent of the total rainfall. The central and eastern regions, which cover 70 percent of the country, receive the remaining 43 percent.
The world's available water per capita is 7 400 m3/year. Generally when per capita water is reduced to 1 700 m3/year or lower, the country or region concerned experiences different types of water stress. In the past, when I.R. Iran's population averaged 19 million, per capita water was about 7 000 m3/year. Now that the population has reached 67 million this figure has been reduced to 1 910 m3/year. Estimating population growth, it is predicted that by 2025 per capita water in I.R. Iran will be around 1 400 m3/year.
Statistics reveal that I.R. Iran experiences drought twice every ten years (for example 1970–1971, 1972–1973, 1983–1984, 1998, 1999–2000, 2000–2001). Based on reports from 2001, drought affected more than 2.6 Mha2 of irrigated agriculture, 4 Mha of rain-fed agriculture and 1.1 Mha of orchards.
The physical area is 165 Mha of which approximately 37 Mha are suitable for irrigated and dryland farming (20 Mha irrigated, 17 Mha dryland) 18.5 Mha for field and horticultural crops (8.2 Mha irrigated farming, 6.4 Mha annually irrigated crops), 2 Mha for horticultural crops, 6.2 Mha for annual dryland crops and 3.9 Mha for fallow. The remaining 102.4 Mha include 90 Mha for pastures and 12.4 Mha for forests.
Due to water resource limitations, currently only 8.2 Mha are under irrigated agriculture which consumes more than 93 percent (84 BCM)3 of total national water supplies (93 BCM). Currently the agriculture sector consumes 93 percent (84 BCM) of the country's renewable water resources (93 BCM) of which 46 percent comes from surface and 54 percent from groundwater resources. Overall irrigation efficiency is 40 percent, which is lower than the world average, but realistic with regard to total agricultural water consumption and the total irrigated area.
Currently, total irrigated agricultural production is 67 million tonnes and concomitant total water resources consumed amount to 84 BCM, i.e. for the production of one kilogram of crop, 1.25 m3 of water is consumed. Estimate and planning analysis indicates that agricultural production should reach 186 million tonnes by 2025. Based on allocated water to the agriculture sector for the target year (93–103 BCM), the country should achieve water productivity (WP) of 1.6–2.0 kg/m3. Based on the role of each unit of water consumed in national production, WP in I.R. Iran is quite low.
Statistics from 2002 reveal that irrigated land under regulated water (dams, diversion dams, river pumping) amounted to 3 Mha. Of this area, only 52.3 percent was equipped with main irrigation and drainage networks
1 Research Associate and Basin Coordinator for the CGIAR Challenge Program on Water and Food (CPWF) international project in the Karkheh River Basin (KRB), Irrigation and Drainage Department, Iranian Agricultural Engineering Research Institute (AERI), P.O. Box 31585-845, Karaj, Iran. Fax: +98-261-2706277; email: firstname.lastname@example.org
2 Million ha.
3 Billion m3.
and 21.6 percent was equipped with secondary irrigation and drainage networks. Out of 8.2 Mha of total irrigated lands, 4.2 Mha were not under secondary irrigation networks and over a small area, on-farm development activities (land levelling, land consolidation) were conducted. These are indicators of unsophisticated irrigation infrastructure activities compared to water supply activities. This causes extra water losses in the consumption phase.
Imbalances between investment and execution of water supply and water demand management programmes has led to lower irrigation efficiency and agricultural water productivity, through water losses, waterlogging and soil and water salinization. Reports indicate that the area of land with drainage problems increased from 16 000 ha in 1977 to 700 000 ha in 2003. The price of privately supplied agricultural water in I.R. Iran is much higher than the price that waterboard authorities charge farmers. In other words the government pays subsidies for agricultural water supply.
Agricultural product losses in I.R. Iran are high (up to 30 percent for fruits and fresh vegetables). Assuming an average agricultural product loss of 15 percent, irrigation water loss through agricultural product loss is estimated to be 12.6 BCM which is equal to 40 percent of all the water stored by reservoirs.
The two Ministries of Energy and Agriculture (called Jihad-e Agriculture) administer I.R. Iran's water resources. Research institutes (e.g. AERI, SWRI in the Ministry of Agriculture or TAMAB in the Ministry of Energy), research centres, water departments in universities and consultant engineering companies (e.g. Mahab-e Ghods) also have important roles in this regard. There are 49 research or education institutes related to water 14 research institutes specifically target water research, 25 societies on water or agriculture, 47 consulting engineers and 178 irrigation manufacturing or design companies (especially for pressurized irrigation systems).
2. The Zayandeh–Rud River Basin
The Zayandeh–Rud River has been the lifeblood of Central I.R. Iran for centuries and is focused around the ancient city of Esfahan. In 1600 Esfahan was one of the ten largest cities in the world; it was sustained by irrigated agriculture using the waters of the Zayandeh–Rud. The city was the capital of ancient Persian kingdoms and remains the cultural heart of I.R. Iran.
2.1 Physical characteristics
Central I.R. Iran is typical arid and semi-arid desert. Rugged mountains of limestone and siltstone, devoid of vegetation, rise sharply from their surrounding alluvial fans built up by seasonal torrents. Most of the area has thin soil overlying the stony alluvial fans, providing little basis for economic enterprise other than rough grazing on the xerophytic vegetation.
Cutting across this monotonous landscape is the fertile valley of the Zayandeh–Rud (Figure 1). The river rises in the bleak and craggy Zagros Mountains that reach over 4 500 m, traverses the foothills in a narrow and steep valley and then bursts forth onto the plains at an altitude of some 1 800 m. However, the splendour of the river is short lived: Reduced towards the east by natural seepage losses, evaporation and more recent extractions for irrigation, urban and domestic uses, the river eventually dies out in the Gavkhouni Swamp, a vast playa of white salt that forms the bottom end of the basin, lying at an altitude of over 1 200 m (Figure 1).
The Zayandeh–Rud Basin (ZRB) naturally is a closed basin. The total length of the Zayandeh–Rud River is some 350 km, but it is the central 150 km of the floodplain to the east and west of Esfahan that provide the basis for intensive agriculture and large settlements. Along this strip soils are deep and fertile, predominately silts and clay loams, slopes are gentle, ideal for the culture of irrigated agriculture built up over many centuries. The river indeed forms an oasis in the desert.
The basin has a predominantly arid or semi-arid desert climate. Rainfall in Esfahan, which is situated at an elevation of 1 800 m, averages only 130 mm per year; most of the rainfall occurring in the winter months
Figure 1. The Zayandeh–Rud Basin (ZRB)
from December to April. During the summer there is no effective rainfall. Temperatures are hot in summer, reaching an average of 30×C in July, but are cool in winter dropping to an average minimum temperature of 3×C in January.
Annual potential evapotranspiration is 1 500 mm, and it is almost impossible to carry out any economic form of agriculture without reliable irrigation. The primary source of water in the ZRB is the upper catchment of the Zayandeh–Rud.
2.2 Irrigated agriculture in the ZRB
The pattern of reliable spring floodwater emerging from the mountains onto flat alluvial plains during the warm spring months makes for an ideal environment for irrigated agriculture in the region. It is little wonder that irrigation has for centuries provided the basis for productive and, at least until recently, sustainable irrigated agriculture. In all respects Esfahan was one of the world's classic oases, irrigated by diversions from the Zayandeh–Rud.
2.2.1 Traditional irrigation
Original irrigation developments relied on three different technologies: Diversions, lifting and tunnelling. The waters of the Zayandeh–Rud were diverted through stone and wood weirs into a complex series of canals that roughly paralleled the course of the river.
For several centuries there were well-established and complex rules for diversion of water from the Zayandeh–Rud. Scrolls dating from 1544 in the reign of Sheikh Bahai spell out water rights for different parts of the river. Almost all of these areas, irrigating several tens of thousands of hectares, remained more or less unchanged until the advent of the modern irrigation era in 1970. Few of the traditional technologies remain.
Modern irrigation, either in the form of large-scale gravity irrigation systems fed by large regulating weirs or electric or diesel-powered tubewells, accounts for almost all irrigation. Traditional canals have been absorbed into the large-scale systems, while many qanats (underground infiltration tunnels for obtaining water) have either fallen into disrepair or have been dried up by adjacent drilling of deep boreholes. These systems are entirely under the control of local communities and may total as much as 40 000 ha.
2.2.2 Modern irrigation
Modern surface irrigation started with the construction in 1970 of major diversion weirs at Nekouabad and Abshar, each diversion weir controlling both a Left Bank and Right Bank main canal (Figure 2). These weirs were designed and built by the same companies involved in the construction of the reservoir, thereby creating a coordinated approach to water control and management in the basin. These four systems have provided the bulk of irrigated agriculture for the past 30 years.
However, one large-scale traditional gravity system still survives, at Rudasht, the most downstream of the irrigation diversions (Figure 2). Even this is in its last years of operation as a new diversion weir has already been constructed and will replace the traditional weir as soon as new irrigation canals are completed. Basic information on irrigation systems in the ZRB is provided in Table 1.
Figure 2. Location and main irrigation schemes in the Zayandeh–Rud Basin (ZRB), Islamic Republic of Iran
All of the gravity irrigation systems are based on modern design concepts brought to Esfahan by French engineers.
The two modern upstream systems at Nekouabad have no significant waterlogging or salinity problems and apart from a few locations where gypsum deposits create difficulties, there are few constraints to productive agriculture. Annual cropping intensity is about 170 percent, with slightly more land cultivated in winter than summer. The main crops in summer are rice, potatoes and vegetables while in the winter barley and wheat dominate. There are substantial areas of perennial orchards.
In Abshar, the middle reach of the modern irrigated areas, cropping intensities are lower, just over 100 percent, with only 32 percent of the area cultivated in summer. Constraints to good agricultural production are drainage problems towards the tail end reaches near the Zayandeh–Rud as well as some saline and gypsiferous soils. Rice is not grown extensively and there are no orchards. Summer crops are mostly maize and vegetables, while winter is dominated by wheat. Annual crops are mostly sugarbeet and alfalfa. Groundwater quality appears to be declining, and there is significant lowering of the groundwater table away from the Zayandeh–Rud.
Table 1. Basic information on irrigation systems in the Zayandeh–Rud Basin
|Name of system||Date of construction||Command area (ha)||Design discharge (m3/sec)||Length of main canal (km)||Name of secondary system canals (km)|
|a) Old systems|
|Nekouabad Right Bank;||1970||13 183||13||13.30||45.0|
|Nekouabad Left Bank;||1970||26 872||45||59.35||76.6|
|Abshar Right Bank;||1970||12 570||15 000||33.50||38.0|
|Abshar Left Bank||1970||23 000||15||36.00||33.0|
|b) New systems Borkhar||1997||18 500||29.00||Not finished|
|Rudasht Left & Right||(*)||47 000||209.20||Not finished|
|Mahyar||In progress||24 000||120.00||Not finished|
|c) Traditional systems||40 000|
* Rudasht is an ancient system being replaced with a new system. All new systems have conjunctive use of surface water and groundwater.
In Rudasht there is moderate to severe salinity and water tables are close to the surface. Cropping intensities are lower than Abshar, falling to 95 percent for the year and 28 percent in summer. This is in an area where significant volumes of groundwater are pumped but the water is low quality. Typically crops are wheat and barley in winter, some cotton and maize in the summer and annual sugarbeet and alfalfa.
The impact of the development of the four major irrigation networks at the same time as the construction of Chadegan Reservoir can be seen in Figure 3, which compares gross irrigated area in 1965 and 2000, as well as the shift in crop types.
The provision of more water with timing better suited to the needs of higher value crops has clearly been highly beneficial and productive at the basin level and for the upper portions of the irrigation systems. But it has had severe effects on the groundwater problems in the tail part of the system; this has led to greatly increased inequity in production and incomes between head and tail end parts of the basin. Head end farmers are perceived, perhaps incorrectly, as profligate water users, at the expense of tail end areas.
Figure 3. Changes in cropped area and cropping patterns from 1965 to 2000 in the ZRB
2.2.3 Recent irrigation developments
In the past few years there has been a large increase in the size of the gravity irrigation network. Two large systems have been constructed at Mahyar and Borkhar, while the Rudasht network has been modernized and a new weir has been constructed.
The Mahyar and Borkhar systems provide surface water to areas where there has been substantial groundwater irrigation for several years. In both areas the water table has been dropping and in Mahyar it is of particularly poor quality. The design intention is that surface water supplies are used by farmers (only to be delivered when annual water availability at Chadegan Reservoir is at or above normal levels) in times of reduced water stress to protect their groundwater resources.
Whether this happens or not remains to be seen. Farmers will clearly value good quality freshwater supplies more than their lower quality groundwater and may try to augment groundwater supplies rather than switch backwards and forwards from groundwater to surface water depending on canal availability. The risk in these areas is that if additional areas under irrigation are established because of additional freshwater supplies, more groundwater will be extracted in dry years to compensate for the lack of surface water supplies. At present cropping patterns in both areas tend to be rather low water-consuming crops: Grapes, sunflower, wheat, melons and millet. But it is possible that freshwater will encourage a switch to high value crops that have higher water consumption such as rice and alfalfa.
A second type of irrigation development has been expanding very recently in the reach of the Zayandeh–Rud between Chadegan Reservoir and Lenjanat. Traditionally irrigation was restricted to gravity use in these areas because of the deep valley in which the river runs. However modern technology has allowed the development of larger areas of fruit and nut trees by installing large diesel pumps along the river and pumping up the hillsides into terraces provided with drip irrigation. Initially the pumping was perhaps 20 to 30 m up from the river, but now huge pumpsets have been installed that pump water right up from the valley to the plains on either side. The current area may be in the order of 10 000 ha and is rapidly expanding. No doubt this type of irrigation development is and will be economic because fuel is cheap and the crops grown are high value, but the impact on downstream water users cannot be discounted.
It seems somewhat contradictory that while large-scale irrigation systems established 30 years ago, let alone the traditional systems that date back hundreds of years, are struggling to obtain sufficient water, new irrigation developments continue apace in the basin.
The ZRB has been experiencing water stress for the past 50 years. Expansion of the irrigated area through major investments in modern irrigation systems, the establishment of large-scale industries which require significant volumes of water and the continuing rapid growth of Esfahan, with a current population of over 2.5 million people, have all depended on the fragile water resources of the ZRB.
Since 1950, strategies have been adopted to increase natural water potential, both through transbasin diversions and reservoir construction. But by 2000 it was clear that demand had continued to grow faster than potential water resource development. As a result there is increased pressure on both water and soil resources. Tail end areas show the greatest stress with reduced water availability, deteriorating groundwater quality, increased soil salinity and declining agricultural production; little water reaches the environmentally valuable Gavkhouni Swamp at the tail end of the Zayandeh–Rud (Figure 1).
It is therefore impossible to avoid the conclusion that current levels of agricultural production are unsustainable under current management conditions.
The ZRB provides a classic example of a closed basin, one where all water is used up within its productive area. Under closed conditions, any change in water use within any one sector will inevitably affect all other water users in the basin and apparent improvements in one sector must be examined at the basin level to determine the impact on other sectors or on other users elsewhere in the basin.
This means that there is no single solution to the current water crisis: Changes at the farm level, system level or basin level undertaken in isolation will not be sufficient to alleviate the current conditions. While specific actions are required at each level, they must be integrated into a total basin-wide management strategy to be effective.
Under these conditions it is clear that some degree of radical thinking is required that will develop and implement a more integrated approach to the water problems of the Zayandeh–Rud. In attempting to move towards an integrated approach, the I.R. Iran–IWMI collaborative research project deals with water management issues at each of the three main management levels (field, system and basin) and then looks at policy issues that aim at integrating water management at the basin level (Murray-Rust et al. 2000; Salemi et al. 2000).
2.3 Field level water management issues
The I.R. Iran–IWMI joint research project concludes that there are still important gains that can be made in terms of water productivity if farmers adopt more effective on-farm water management techniques. These include better matching of water application to crop and soil water requirements, improved land levelling, correct furrow shaping, mulching, use of flexible polythene pipes for on-farm water conveyance and micro-irrigation.
However, modelling indicates that if farmers adopt all of these methods (and most can only adopt a subset of the improvements on any given farm) then water productivity will increase by a maximum of 33 percent over the next 20 years, from about US$0.12 to US$0.16. This is not a dramatic improvement on an annual basis and the gains must be offset by deducting the increased capital input and labour costs involved. Further, the higher benefits will likely only be obtained when farmers switch from lower value field grain crops to higher value fruits and vegetables and they cannot all do this unless there is a change in the overall marketing and processing sector.
The research also concludes that improvements in on-farm water management do not result in water savings when considered from the basin perspective. If a farmer uses less water through improved water management techniques, the water he does not use will quickly be used by other farmers. Water productivity will clearly be greatly increased, but it will not result in any amelioration in water shortages at system and basin levels.
There is a need for continued research on appropriate water management techniques for different soils and crops. However, the research so far concludes that the best way for farmers to adopt more effective water management techniques is for them to move into higher value crops wherever possible. Micro-irrigation techniques should only be actively promoted when the value of the crop is significantly higher than current cropping patterns because the capital costs of micro-irrigation are high and must be offset by growing more profitable crops.
The research recognizes that some farmers have already adopted a number of improved management techniques. It recommends that a socio-economic survey that includes both adopters and non-adopters be conducted to see what factors appear to encourage or discourage farmers in the adoption of potentially important water management techniques.
Deficit irrigation techniques also need to be promoted because these are an important response in years when water supply is lower than normal. However, supplies must be augmented in years when more water is available to offset inevitable increases in soil salinity associated with deficit irrigation.
2.4 Irrigation system level water management issues
Despite the recognition that water is scarce throughout the basin and there is a need for improved management, the research finds some shortfalls in the overall information required to implement an effective programme of water management. The most important data that are lacking are accurate estimates of actually irrigated area and cropping patterns for each irrigation system. Without these data it is impossible to more precisely match water deliveries to individual irrigation systems to actual demand. As a result, irrigation deliveries to irrigation systems are largely determined by designed areas and cropping patterns and estimates of estimated potential evapotranspiration.
The research strongly recommends that major efforts be made to improve information on irrigated areas and cropping patterns using a combination of field surveys and remotely sensed data. Project results show it is not difficult to use satellite images to estimate irrigated area, crop type and actual evapotranspiration and the results are sufficiently accurate to guide managers and policy-makers.
Part of the problem stems from the historical division of responsibility for water and agriculture into separate departments. But data from both departments are essential for improved water management. The research strongly recommends that data be collected on the basis of the canal layout at main and secondary levels, rather than the current mix of water for canal levels and agriculture by administrative districts.
The research also strongly recommends the adoption of methods for benchmarking of irrigation performance at system and subsystem levels so that actual values of water productivity and matching of water deliveries to crop–water demand can be determined.
The research recognizes that there is a lack of useful data on groundwater use for irrigation, although the research results indicate groundwater use in major irrigation networks is significant. A survey is required of actual water use practices using both canal and groundwater by representative farmers, so that total water use for agriculture can be better estimated. This is important both because some surface water seeps into groundwater and is used effectively rather than being wasted and because groundwater levels in many irrigation networks are declining.
There needs to be a review of current water allocations between irrigation networks as well as within irrigation networks. Current allocations fall half-way between equality between networks and favouring head end systems.
The research shows that there are productivity increases at system and basin levels if water is used on the most productive soils, but this has negative implications for equity between head and tail end water users. The research also recommends special attention be paid to the new irrigation networks of Borkhar and Mahyar which are still being developed. Research suggests these networks are at high risk of soil salinization and groundwater depletion because the provision of modest amounts of good quality canal water may encourage farmers to pump even more that at present because they can mix poor quality groundwater in larger volumes.
2.5 Basin level water management issues
The research concludes that agriculture will be the sector with the lowest overall priority. This means that whenever there are deficits in water below planned conditions, agriculture will take a disproportional reduction in water availability, as occurred during the 2000 and 2001 drought.
While recommending that further investigations be made that can help augment existing or planned water supplies, water resource developments cannot per se solve the problems of the basin and demand projections suggest that it will be impossible to find sufficient water to meet unregulated demand after 2020.
To make matters more complex, new irrigation developments in Mahyar, Borkhar and along the upper reaches of the Zayandeh–Rud seem to have been improperly evaluated in terms of actual water availability. This does not mean the developments are incorrect or inappropriate, but that their impact on other water users has not been properly evaluated. This is a clear example of the need for integrated modelling of water resources at the basin level.
The increase in groundwater pumping over the past ten to fifteen years is alarming. Although exacerbated by the recent drought, the overall trends for the past decade are declining water tables, increased installation of pump sets, deepening of boreholes and, in tail end areas, declining quality of groundwater. Despite these trends, there is no effective monitoring or regulation of groundwater exploitation at the basin level. The report anticipates long-term damage to groundwater resources throughout the basin unless an effective basin-wide groundwater monitoring and regulation system is established.
Parallel to this increase in pumping is the apparent continued increase in soil salinity. This is a broad trend from head to tail throughout the basin and in individual irrigation networks in the lower half of the basin. Increased pumping means that salts accumulate in soils without being properly leached.
The research finds that although there is much data available in individual departments and agencies there is no effective coordinated database that is a common public resource useful for integrated management purposes. Given the strong sense of the report that uncoordinated unilateral approaches are not the way to integrated water management, it is essential that data from different sources are made available to facilitate a more coordinated approach to water management.
A strong recommendation is therefore given for the development of an effectively coordinated and managed database that brings together information from all different sectors that can be used to support integrated water management at the basin level. This database then provides the basis for testing different models of water allocation and use into the future and developing appropriate management actions when water supplies are significantly different from average conditions.
2.6 Policy issues
The research stresses that while independent actions at field, system and basin levels can lead to improvements in water productivity, greater benefits will accrue if there are strong linkages between these different actions.
The report feels that there is a need to have a clearer and more transparent system of water allocation between sectors so that managers within each sector know how much water they will have each year. The allocation priorities should be based on demand under normal conditions backed up with modifications to be adopted in exceptionally dry years. Assuming agriculture is likely to be the lowest priority, some form of drought insurance scheme could be adopted to compensate for lost production in dry years.
The research strongly recommends that a basin level water management authority be established that has executive responsibility, rather than an advisory role. With water becoming increasingly scarce at the basin level in the foreseeable future so that changes in any one water use automatically affect all other water users, it is no longer possible to split management between different agencies. Instead, a provincially based water management authority has to play an active role in assessment and monitoring of water resources, allocation of water between sectors and close regulation of the water sector.
While accepting this is a complex and contentious proposal, evidence from other countries indicates that as water resources become increasingly stressed there is a need for increased central control over water resource management and regulation.
In the longer run, the research recommends that an aggressive policy supporting very high value crops, backed up by investment in agro-industrial processing is the best strategy for supporting farmers in the ZRB given the overall shortage of water. Low prices and low productivity of field grain crops make their widespread cultivation an ineffective and unsustainable use of scarce supplies of good quality water. Water productivity and farm incomes can only be improved by switching to higher value crops that use less water, such as fruits, nuts and vegetables.
3. Karkheh River Basin
The Karkheh River Basin (KRB) is located in the west to southwest of the Zagros Mountains at coordinates 56°15;34' – 58°30' north latitude and 46°06' – 49°10' longitude (Figure 4). The area of the basin (inside I.R. Iran) is 50 764 km2 of which 27 645 km2 comprise mountains and 23 119 km2 are plains and hills. The mountainous areas of this basin are mostly in the eastern and central parts. The plains, which are mostly in the northern and southern parts, cover almost 45 percent of the basin area.
Figure 4. Geographical location and boundaries of the KRB
Based on hypsometric studies, 75 percent of the basin is located at altitudes of 1 000 to 2 000 m and 0.6 percent of the basin is above 2 500 m. Eventually the slope of the basin decreases and gently passes Hawr al Azim wetland, the outlet of the KRB.
Based on general hydrological classification of basins in I.R. Iran, the KRB is identified as one of the sub-basins of the Persian Gulf Great Basin. From the north, the basin encompasses the Sirvan, Ghezel Ozan and Gharachai Rivers, from the west the I.R. Iran–Iraq Border Rivers, from the east the Dez River and from the south up to part of the western border of I.R. Iran.
The pattern of precipitation in the KRB is Mediterranean. Rainfall in the basin is characterized by winter rain and then autumn and spring rains. Annual precipitation is 219 mm in Hamidieh (the southern part of the KRB) to 765 mm in the north.
The hottest areas of the basin are located in the south. The coldest areas are found at altitudes exceeding 3 000 m, mostly in the north and northeast.
Evaporation in the KRB varies from 1 800 to 3 600 mm depending on altitude. The average annual evaporation varies from 1 894 mm (in Mahidasht at an altitude of 1 350 m) to 3 561 mm (Abdol–Khan Station at 40 m).
The KRB has both surface and groundwater resources. In 1994 the share of agricultural water consumption from these resources was 3.956 BCM. Following completion of irrigation networks under the Karkheh Reservoir scheme, this was increased to 7.433 BCM (a 90 percent increase).
Both surface and groundwater are of good quality but the quality of groundwater in the southern plains has deteriorated slightly. Potential surface water resources in the KRB amount to 7.374 BCM. In wet years this can be doubled and in dry years it can be reduced by 50 percent.
The KRB encompasses one of the poorest regions of I.R. Iran. It has very inadequate infrastructure and was severely affected by the war with Iraq. Enhancing low food production under both dry farming and irrigation conditions is of crucial importance to increase farmers' per capita income.
Two major agricultural production systems prevail in the KRB. Dryland farming occurs upstream and fully irrigated farming in some upstream zones and all downstream zones of the KRB. The dryland areas are well established and cover most of the basin's arable land, occupying 894 125 ha; irrigated land occupies 578 862 ha but this is expected to expand by 340 000 ha with the completion of the Karkheh Reservoir.
The KRB is a water-deficient area and droughts are becoming a permanent feature. Due to water shortages and degradation of land and water resources, the livelihoods of rural communities are at stake.
In 1994, 3.956 BCM of water was used for agriculture in the KRB. Out of this amount, 36.8 percent was groundwater and 63.2 percent came from surface water resources.
Quantatively, the highest volume of groundwater is extracted from Gamasiab, followed by Gharasou sub-basin in the north of the KRB.
In the entire KRB area, the highest consumption of surface water resources occurs in the southern (lower) part.
Based on 1994 statistics, out of 4 157.4 MCM4 of consumed water resources, 2 504.6 MCM (60.2 percent) was surface water and 1 653 MCM (39.8 percent) was groundwater. The share of agricultural water consumption in 1994 was 94.17 percent. Therefore the KRB is completely devoted to agriculture (industrial and mining activities accounted for just 0.32 percent of total water consumption).
3.1 Optimization of the Karkheh Reservoir Water Allocation Plan
The general objective of the plan is efficient use of Karkheh Reservoir water (in the lower KRB), considering technical, socio-economic, cultural and environmental parameters. The specific objectives of this plan are:
The plains' area addressed by the plan (340 000 ha) is located between Khuzestan and Ilam Provinces. The command area of irrigation networks and the area supplied by the Karkheh River include the northern part of the lower KRB (115 500 ha) and the southern part of the lower KRB (229 500 ha).
The plan has two phases:
The useful life of Karkheh Reservoir, Hamidieh Diversion Dam and the diversion-regulation Pay-e-pol Dam is considered to be 50 years. The life for irrigation networks under dams is expected to be 30 years. Irrigation
4 Million cubic meters.
networks for Hamidieh, Zamzam and Ghods were constructed in the past and are currently operating. Table 2 lists phases of different plan components. Based on the information provided in Table 2 there is a considerable amount of work to do in the next eight to ten years, especially with regard to completion of the irrigation and drainage networks and efficient use of water for agricultural production in the lower KRB.
Table 2. Phases of the main components for optimizing the KRB water resource plan
|Plan components||Study phase||Construction phase||Progress (%)|
|Pay-e-pol regulating & diversion dam||1971||1998||1997||2004||70|
|Hamidieh Diversion Dam||–||–||1951||1957||100|
|Pay-e-pol main canal||–||–||1997||2009||30|
|Main networks of the Pay-e-pol plains (except Avan)||–||–||2004||2013||–|
|Avan Plain (main network)||–||–||1992||1997||100|
|Avan Plain (secondary network)||2001||2004||2004||2009||–|
|Dosalegh Plain (secondary network)||2003||2007||2005||2010||–|
|Arayez Plain (secondary network)||2005||2009||2007||2013||–|
|Bagheh Plain (secondary network)||2008||2009||2010||2013||–|
|Conveyance tunnel (Abbas Plain)||–||–||1997||2004||95|
|Main canal of Abbas Plain||–||–||2000||2004||–|
|Abbas Plain (main network)||–||–||2001||2005||–|
|Abbas Plain (secondary network)||2002||2005||2004||2010||–|
|Ein Khosh and Fakkeh (main network)||2003||2006||2005||2013||–|
|Ein Khosh and Fakkeh (secondary network)||2006||2010||2007||2013||–|
|Mosian (main network)||2007||2010||2005||2013||–|
|Mosian (secondary network)||2008||2010||2010||2013||–|
|Koosar (main network)||–||–||2000||2004||–|
|Koosar (secondary network)||2004||2006||2006||2009||–|
|Main canal of DA||–||–||1998||2008||–|
|East of DA (main network)||–||–||1998||2011||–|
|East of DA (secondary network)||2004||2007||2007||2013||–|
|West of DA (main network)||1998||2004||2004||2011||–|
|West of DA (secondary network)||2001||2007||2006||2013||–|
|Main canal of Chamran||–||–||1998||2008||–|
|Chamran and development (main network)||1997||2002||2004||2013||–|
|Karkheh Noor and development (main network)||2003||2006||2004||2013||–|
|Chamran (secondary network)||2003||2005||2006||2012||–|
|Development of Chamran (secondary network)||2005||2008||2008||2013||–|
|South of Karkheh Noor (secondary network)||2005||2009||2007||2013||–|
|Development of Southern Karkheh Noor and northeast||2008||2010||2009||2013||–|
Dasht-e Azadegan region.
With more regulated flow to the Karkheh Reservoir due to construction of hydropower dams in the upstream basin and also revision of cropping patterns and improvements in irrigation efficiency (through modern irrigation techniques) it is expected that the cropped area could be increased to 345 000 ha.
Based on Phase 1 studies, water requirements for proposed cropping in areas downstream of Karkheh Reservoir are estimated to be between 14 500 to 20 050 m3/s.
The proposed cropping pattern and relevant water requirements are based on the classification of the region into three areas. In this classification, homogeneity in parameters for soil and water resources has been considered.
Water resource development and availability of water for irrigated areas under the Karkheh Reservoir have been studied, taking into account water resource development upstream of the KRB and the environmental needs of the Hawr al Azim wetland.
3.2 Challenges for development of irrigated areas in the lower KRB
There are plans for at least 341 000 ha of land under the Karkheh Reservoir scheme to be irrigated through irrigation networks but there is a minimum water deficit of 18 000 MCM. Consultants' measures to overcome this problem are provided hereunder.
3.2.1 Construction of Azad and Javeh dams
I.R. Iran's water industry wants to construct Azad and Javeh dams on Sirvan River tributaries, because:
3.2.2 Optimization of water consumption and allocation in the KRB
Almost all projects in the basins of I.R. Iran, including the KRB, have excluded basin optimization. Research has been conducted at the project level not the basin level. Therefore, there is a need for I.R. Iran's water industry to analyse the KRB based on optimization of water resources and allocation at the basin scale. For the optimization, the following influences should be examined holistically:
Also, the following questions should be answered:
There is a need to revise evaluation and estimates with regard to, inter alia, cropping patterns, water requirements, irrigation efficiency, percentage of water provided for environmental needs and the extent of expansion. Factors to consider are:
3.3 Salinity and waterlogging in the lower KRB (Dasht-e Azadegan region)
The KRB is one of I.R. Iran's top-ranking basins. Despite overall potential in terms of climate, soil and water resources, agricultural water productivity in the lower and downstream areas of the KRB is very low. This is mainly due to the harsh climatic environment in the south and lack of sound agronomic, water and salinity management practices. In the near future 340 000 ha are scheduled to be irrigated under different irrigation networks. The lower part of the KRB region is typically hot and quite arid so agricultural production depends on irrigation. This area is planned for further development in line with the adjacent model of Dez irrigation district.
Waterlogging and soil salinity are the major threats to water productivity and sustainable agricultural production in the lower KRB; thus guidelines based on sound and relevant research are urgently needed. In addition to the national food security objective, improving the well-being of the agricultural communities in the mentioned lower region is exceptionally important to minimize socio-economic problems related to local migration of farmers and security issues among the I.R. Iran–Iraq border communities.
Major factors causing soil salinization in the lower KRB can be classified as follows:
The Dasht-e Azadegan region (DA) is one of the main plains in the lower KRB. Karkheh River diverts towards the northwest of the region near the city of Hamidieh and eventually joins the Hawr al Azim wetland. The DA region is located to the furthest south across the delta of Karkheh River, 20 km west of the city of Ahwaz. The total area is almost 200 000 ha, 95 000 of which spread over the current civil projects of the DA region. This plain is located between 47'55 to 48'30 east and 31'15 to 31'45 north and its height above sea level varies between 3 to 12 m. The main physical constraints include salinity and sodicity of the soil, high levels of saline groundwater, soil permeability and drainage restrictions. In fact, almost all of the farmlands in this region have salinity and sodicity problems. The results of semi-detailed soil survey studies indicate that approximately 80 percent of the farmland of the DA region has both low or high salinity and sodicity; statistics indicate:
Available data and surveys show that the problem of soil salinity in the DA is magnified due to lack of farmers' knowledge and skills and unavailability of new and improved farming practices. Generally, the main cause of soil salinity in the lower KRB is the high water table, often less than 2 m, usually 1.2–3 m below the soil surface. If unaddressed, the problem is likely to worsen with the current plans for the expansion of irrigation networks.
Although main drains have been constructed in the area, they are not functioning properly. This is mainly due to technical problems (e.g. slope of the drain) and also problems concerning the outlets. Gravity drainage to outlets is not possible and pumping is required.
4. Conclusions and recommendations
During the past 20 years, and especially in the first, second and third five-year national development acts, many activities have been irregular or unsystematic. However, in recent years, huge investments have been made in the construction of dams and new irrigation and drainage networks. Unfortunately many of the projects were mostly development-oriented and less attention was given to their operation and maintenance. This factor, as well as rising costs, gradually reduced the performance of irrigation networks and has been juxtaposed by land drainage and salinization problems.
Fortunately at the end of the second national development act and especially in the third act, the problem was raised and special focus was put on the need for water management and improvements in the operation and maintenance of irrigation projects. This governmental concern has continued into the fourth five-year national development act.
To promote efficient water use, in the past decade, institutes have been improved in an attempt to enhance the management and planning of water resources, different water laws and the organizational structure of water. Different laws have been developed by the government and approved by parliament. Among the most important national acts is the "Equitable Distribution of Water Law". Also different infrastructure activities both in the government and private sector have been developed and executed.
However, water organization in I.R. Iran still needs improvement, modification or new structure, especially with respect to recent drought indices.
To achieve efficient water use, the Ministries of Energy and Agriculture have initiated linkages and cooperation. However despite some progress, it appears that close linkages, or even transfer of water management authority from one ministry to another, are not sufficient solutions for the optimum use of water in I.R. Iran. Therefore we should have a new vision for water management and its organization, based on new international policies and concepts for water management, to make our policies and decisions more dynamic and comprehensive.
Efficient water use and improvements in agricultural water productivity (at least double the present volume) must be addressed in the next 20 years. This challenge needs innovative laws and institutions for water management and more participation by stakeholders in parallel with infrastructure activities (e.g. completion of irrigation networks, on-farm development activities), capacity building and applied agricultural engineering research.
Specific conclusions and recommendations for the ZRB and KRB basins are provided hereunder.
4.1 Zayandeh-Rud Basin
Basin development is normally a three-stage process with a relatively smooth transition between exploitation, water supply management and optimized allocation. The experience of the ZRB shows a much less encouraging picture. Increased water supply in each phase of development still fell behind demand growth. This is why in the past 50 years, the basin has remained generally water stressed. There is no interbasin integrated water management that distributes water in times of shortage uniformly between different uses, or even within a particular water use. The implication is that the basin will remain vulnerable to unsupplied demands and deficits of more than 10 percent will lead to significant stress in downstream areas.
The need for a more integrated approach to basin management as well as a set of long-term plans for re-allocation of water among sectors is therefore required to cope with the anticipated water deficits that will arrive in or around 2020.
Without transbasin diversions, the ZRB would not be able to meet existing and upcoming demand for water. The growth rates assumed are all modest: With annual growth rates of 20 percent per decade in all sectors the basin will be experiencing major deficit before 2020. Once supplies drop below historic averages, however, agriculture will take a significant cut in water supplies. If total supplies are only 10 percent below average then even in 2020, the most favourable year in the developed scenarios, total water supplies for agriculture will be less than those at present. So rapid growth must be decelerated or plans will have to target certain sectors to give up their share of water to other users.
The following technical, policy and research issues should be considered for water and irrigation management in the ZRB:
Technical issues at field, system and basin levels
Policy issues that relate to various aspects of water management
Research issues that require further study and investigation
4.2 Karkheh River Basin
Soil salinity and waterlogging, in addition to other weaknesses in agricultural water productivity improvements, are the major constraints in the lower KRB. The problems are physically related (soil, hydraulic gradient), but are mainly human-induced and can be managed by proper measures, including infrastructure activities (hard) and to a greater extent by improved water management (soft).
Hard option: Irrigation and drainage networks are developing in the area, but to date are mainly limited to the main canals/drains; lower order canals/drains that are necessary for the implementation of proper water management are lacking.
Soft option: Many studies and network designs (at the project level) are being conducted by consultant engineers and expert organizations; however these are mostly classic studies and application of new approaches and tools, such as the use of proper models relevant to various levels, are lacking or not applied sufficiently. This weakness is also evident in comprehensive plans for the basin.
Detailed studies are conducted mainly at the project level. There are no detailed or semi-detailed studies for the basin level. There is a critical need for clear and well-defined strategies and policies for water management in Khuzestan Province, through which two-thirds of the country's water flows, and especially in the KRB.
Wetland interactions with upstream irrigated agriculture developments could be optimized and managed using proper planning and coordination inside and outside the country.
Water limitations and all of the aforementioned issues suggest that we should efficiently use water in the KRB and the policy for water productivity improvement in the KRB should be given higher priority.
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Keshavarz, A., Heydari, N. & Ashrafi, S. 2003. Management of agricultural water consumption, drought, and supply of water for future demand. Proceedings of the 7th International Conference on Sustainable Development and Management of Dry-lands in the 21st Century, 4–17 September, 2003, Tehran, Iran. (In Persian.)
Mahab-e Ghods. 2005. Optimal allocation of Karkheh River water resources. Studies of agricultural and agricultural economics. Tehran, Iran, Mahab-e Ghods Consulting Engineers. (In Persian.)
Mahab-e Ghods. 2004. Systematic and comprehensive in optimal allocation of Karkheh River water, report of planning for Karkheh River. Tehran, Iran, Mahab-e Ghods Consulting Engineers. (In Persian.)
Mahab-e Ghods. 1993. Soil reclamation studies of Dasht-e Azadegan development. Irrigation and drainage plan of Karkheh. Tehran, Iran, Mahab-e Ghods Consulting Engineers. (In Persian.)
Mahab-e Ghods. 1992. Studies of agricultural development plan of Dasht-e Azadegan. Irrigation and drainage plan of Karkheh. Tehran, Iran, Mahab-e Ghods Consulting Engineers. (In Persian.)
Management & Planning Organization. 2003. Document on I.R. of Iran outlook and long-term strategies toward year 2025 (basic policies of the country in the fourth national development plan). Tehran, Iran, Management and Planning Organization. (In Persian.)
Ministry of Energy. 2002. Comprehensive plan for water resources and strategies and scenarios of water resources development. Tehran, Iran, Deputy of Water, Ministry of Energy. (In Persian.)
Ministry of Energy. 2003. Long-term development strategies for Iran's water resources. Tehran, Iran, Iran Water Resources Management Company, Public Relations and International Affairs Bureau.
Ministry of Jihad-e Agriculture. 2003. Duties and responsibilities of Ministry of Jihad-e Agriculture, Deputy of Soil and Water. (In Persian.)
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Murray-Rust, H., Salemi, H.R. & Droogers, P. 2000. Water resources development and water utilization in the Zayandeh-Rud basin, Iran. Iran–IWMI Collaborative Research Project, Research Paper No.14.
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Soil and Water Consultant Engineers. 2001. Irrigation and drainage network of the areas in Shahid Chamran plan. Study phases I, II, Report of Land Classification. Part II. Tehran, Iran, Ministry of Energy, Khuzestan Power and Water Authority, Soil & Water Consultant Engineers. (In Persian.)
1. The need for water resource allocation
As a basic natural resource and an important strategic resource, water is vital for socio-economic development and environmental protection. To some extent, water availability has already become an important constraint in deciding whether the future economy of a country and region can develop quickly and whether societal status remains stable. Currently, freshwater deficit has become a worldwide issue and China is no exception. There are two main reasons for water shortages: Decline in natural supply and improper water use development strategies.
1.1 Water shortage in China
Spatially, water is more abundant in the south and east and in short supply in the north and west water distribution is uneven. The distribution of annual precipitation is also non-uniform and in most areas four months of continuous rainfall account for approximately 70 percent of the total annual volume. Each year there are major fluctuations in rainfall so in some years volume is high and in others low, resulting in shortages.
1.2 Improper water resource development strategy
Due to socio-economic development, the demand for water is growing daily. Driven by economic interest, some areas have paid much attention to water demands from various sectors; the environment has subsequently been neglected and ecological degradation has resulted. Consequently sustainable socio-economic growth has been threatened.
Water use efficiency also differs among sectors. More water may be directed to the industrial sector to maintain the economy but at the expense of other areas and uniform water supply. On the other hand, among some basins or regions, due to poor management and inequitable allocation, downstream production and water demand have been neglected so upstream users can improve their lives; thus the downstream environment deteriorates, water use efficiency is low and local water usage is uneven.
In the industrial sector scenario, attention was given to water resource development and usage, but neglected water-saving exercises and protection. Moreover massive sewage discharges occurred in waterbodies without any treatment, seriously polluting local freshwater that may have otherwise been used, thus exacerbating the water shortage situation.
The Chinese Government now realizes the need for water allocation strategies and the development of water conservancy societies to promote healthy and stable socio-economic development and protect the natural environment.
2. Equitable water resource allocation strategy
Eqitable water resource allocation means "in the scope of a basin or specific region, conforming to efficient, fair and sustainable principles, using various engineering or non-engineering measures, following market economy rules and resource allocation criteria, employing various methods and measures including judicious demand control, safeguarding effective supply, maintaining and enhancing the natural environment and distributing different available water sources among regions and water departments". The goal is to foster benign distribution, satisfy socio-economic and ecosystem water demand, obtain optimum benefits from limited
1 Water Resources Department of China Hydroelectric Scientific Institute, Beijing 100044 China.
supplies and promote sustainable development. Therefore water resource allocation should follow the "3E" decision-making mechanism for social justice (Equity), economic efficiency (Efficiency) and ecological protection (Ecology) in order to address coordinated socio-economic and environmental development in terms of time, space, quantity and quality.
However it is not advisable to pursue only one goal. Considering equity but neglecting efficiency and ecology will not result in the effective allocation of water resources. Likewise, singular implementation of the other Es without their counterparts will also fail to produce results. Therefore they need to be balanced in order to realize sustainable development.
3. Influences of water allocation strategies on ecology
Given the significant influence of water resource allocation on the ecological environment, the region's water resources and socio-economic status, China has developed or is carrying out water resource allocation strategies and has obtained relatively good results. Examples of these strategies at basin and transbasin levels are provided hereunder.
3.1 The Heihe Basin
In the Heihe Basin precipitation is scarce, evaporation is intense and water resources are in extremely short supply; these constraints generate anomalies among basin economies and ecologies, in middle reaches and downstream areas as well as interprovincial governance. Because the Heihe Basin encompasses Qinghai, Gansu and part of Inner Mongolia, benefit adjustment is complex and the basin management issue is prominent. Therefore, an authoritative, highly effective and coordinated basin management system must be established and water resources should be managed and deployed uniformly; the main thrust is equitable allocation. In order to resolve these problems and ensure socio-economic development and ecological rehabilitation in Heihe Basin, in April 1996, the Ministry of Water Resources established the Heihe Basin Administrative Bureau. After governmental authorization, in January 2000, the bureau officially started its mandate in Lanzhou City. With regard to the water use situation in Heihe, a water allocation strategy for the basin was proposed. Headstream protection via afforestation was the objective for the upstream area; water-saving enhancements in large-scale irrigation areas were implemented for the middle reaches; the third goal was maintaining the natural environment of the downstream areas traditional water usage and grazing methods had to be altered to protect the natural vegetation.
Under this strategy, the volume of water needed for the middle reaches has been assured; by 2010 downstream groundwater levels should be restored to their former levels in the mid- and late 1980s. The water volume entering East Juyanhai can be maintained annually and West Juyanhai also has administered water levels. The overall ecological environment of the basin has been improved, but it is noteworthy that, after water-saving measures had been implemented in the middle reaches, the groundwater level dropped and the ecology degenerated. These issues need to be researched and resolved.
3.2 The Ningxia region
Ningxia is located in the arid and semi-arid area of Northwest China; annual precipitation is scarce, evaporation is intense and local water resources are in extremely short supply. The Yellow River has become the important water source to support socio-economy and to maintain the natural environment. At present, demands related to industrial and agricultural production and for human welfare in the Ningxia Chuan area and Yanghuang irrigation area can be satisfied and there is no critical water deficit. But in the southern mountainous area, precipitation is scarce and there are no large rivers. Agriculture basically depends on rainfall and local water deficits and soil erosion are serious; thus the ecological environment is extremely frail. According to our research, although the present water supply for the Ningxia Chuan area may be satisfied, owing to future socio-economic development, industrial water demand will increase sharply. If no water-saving measures are taken, water shortage in the Ningxia Chuan and Yanghuang irrigation areas will climb because of lower available water from the Yellow River; irrigation peaks and water deficits in the southern mountainous area could reach as high as 18.5 percent. Therefore, water-saving infrastructure needs to be implemented comprehensively, and saved water should be transferred to industrial and Yanghuang irrigation areas. Wastewater treatment should be upscaled in basins of the southern mountainous area, the Jinghe River Diversion Project should commence and human and livestock drinking water facilities to guarantee potable water supply in rural should be realized. Artificial water supply should be expanded to remedy problems generated by water-saving measures such as water table drop and ecological deterioration. With respect to future water shortages, the South to North Water Diversion Project should be taken into account.
Under this allocation strategy, the Ningxia Chuan area will not experience severe shortages, deficits in the southern mountainous area will be alleviated considerably, the water shortage rate will be curtailed to 12.1 percent and water distribution will be equitable. Future supplies for industry, agriculture and domestic water will be assured in Ningxia. Available water supply in the southern mountainous area may increase, carrying capacity may be enhanced and rural water supply may be guaranteed. Through artificial means, we can maintain the stability of lake surfaces in the region.
3.3 Transbasin diversion the South to North Water Diversion Project
The South to North Water Diversion Project is a significant strategy to alleviate basin water anomalies in China. The north lacks water, but it is abundant in the south. Via the project, we will transport water from the Yangtze River to water-deficient areas such as the Yellow–Huaihe basins, the Jiaodong area as well as the northwest inland river area to alleviate the chronic water usage situation and to maintain the natural environment. After many years of planning and discussion, three water diversion lines have been formed (the east line, the median line and the west line) to connect with the Yangtze, Yellow, Huaihe and Haihe Rivers. Currently, east and median line projects have already begun and the west line project is being planned. The huge water diversion project will inevitably exert profound influence on the ecology of the source area and that of the receiving basins. In line with our research on the Haihe River Basin reception area, we have established three water resource allocation options: (1) Without the Project, continue the present water resource development plan including maintenance of the present water transfer activity (deep and shallow groundwater exploitation to meet socio-economic consumption needs as far as possible); (2) without the Project, apply water resource development with environmental protection being the core mandate and stop groundwater exploitation of deep and shallow layers, restoring ecosystems such as lakes and wetlands; (3) with the Project, by 2010 and 2030, guaranteed water supply to the Haihe River Basin will be 6.93 billion m3 and 10.33 billion m3 respectively.
If we continue with option 1, the Haihe River Basin ecosystem will suffer irreversible harm and regional economic development will be unsustainable. If we adopt option 2, then socio-economic development will be restricted considerably without an external water supply. Therefore, if the Project is not carried out, in ten to 30 years, the Haihe River Basin will be torn between economic development and ecological protection and will be unable to realize sustainable development. If the Project is constructed, water supply conditions in the basin will change with concomitant improvements in the environment and effects on socio-economy.
Equitable water resource allocation is an important tool to coordinate competition among basin water users, local users as well as departmental users. The cases of basin allocation (Heihe), regional allocation (Ningxia) as well as transbasin allocation (the South to North Water Diversion Project) indicate that water allocation has a profound influence on the ecological environment. If the allocation is appropriate, it may sustain the environment, otherwise it may damage or cause the loss of ecological functions. Therefore water resource allocation must have a macroscopic strategy, focusing on equity, efficiency and ecological protection, as well as a view to the long term.
Pei Yuansheng, Wang Jianhua & Luo Lin. 2004. Analysis of influence on water ecology environment of Haihe Basin by the South to North Water Diversion Project. Ecology Transaction, 10: 2116–2123.
Pei Yuansheng & Zhang Jinping. 2006. Generalized water resources allocation control structure. Resources Science, 3: 3–5.
Pei Yuansheng, Zhao Yong & Lu Chuiyu. 2006. Water cycle responding research for regions with reasonable allocation. Resources Science, 3: 6–9.
Zhao Yong, Pei Yuansheng & Zhang Jinping. 2006. Research of water consumption of Ningxia Hetao irrigated areas. Resources Science, 3: 10–13.
1. Administrative organization
The Ministry of Agriculture and Hydraulic Resources is in charge of water resources (mobilization and usage) and agricultural production as well as drinkable water (SONEDE is the state company responsible for potable urban water and DC/GR is responsible for potable rural water). The Ministry of the Environment, among other responsibilities, is in charge of studies on environmental impact analysis, environmental systems' surveillance and urban hygiene (ONAS: The National Office of Cleansing).
In Tunisia, integrated water management is underway and is governed by:
2. Water resource plans
Table 1. Evolution of mobilized resources
|Nature des ressources||Ressources|
|Ressources mobilisées (3)|
|Eaux de surface||2 700||2 100||1 250||1 480||2 010|
|Eaux souterraines||1 970||1 970||1 500||1 750||1 870|
|– Nappes phréatiques||720||720||700||750||720|
|– Nappes profondes||1 250||1 250||800||1 000||1 150|
|TOTAL||4 670||4 070||2 750||3 230||3 880|
|Taux de mobilization (3/2)||–||–||68%||79%||95%|
|Eaux usées traitées||250||200||85||148||210|
Source: Water 21. Agricultural Ministry (2000).
1 Ministry of Agriculture and Hydraulic Resources, Tunisia.
3. General context of water management
460 m3/per capita in 2000 to increase to 345 m3/per capita in 2025;
65 percent of water resources have salinity exceeding 1 g/litre
Table 2. Water demand increases via sectors
|SECTEUR D'USAGE||1990 Mm3||2000 Mm3||2010|
|IRRIGATION||1 575||2 165||2 540||80|
|DEMANDE TOTALE||1 920||2 640||3 165||100|
The future increase in demand is related to:
Addressing water use rationally in most sectors, particularly irrigation, is needed to:
4. General framework of the water management policy reforms
– achievement of the programme for mobilization of conventional water resources;
– development of the use of non-conventional water resources (desalinated, recycled and saline);
– integrated management, conservation and protection of water from pollution;
– setting up instruments to manage demand in various sectors in order to reach water economy of 30 percent in every sector by 2030.
Tunisian water policy has always been accompanied by complementary economic and institutional measures:
Efforts are made to ensure contributions from water users, particularly for potable rural water and irrigated agriculture, which has local economic value or to encourage agricultural production that is not vulnerable to foreign competition (citrus crops, dates, olive oil, fruits or market gardening).
Irrigated agriculture is promoted to enhance its role in regularizing the market and to complement rain-fed agriculture which is very important (in the Maghrebin context, especially for cereals and fodder crops that are necessary for livestock production and milk in particular).
5. Potable water management and hygiene policy
Although relative demand for potable water has declined, the need for quality and hygiene called for SONEDE to create an economic water strategy based on technical and socio-economic aspects.
System regulations are being revised and advanced metering and management techniques that make use of the latest technology are being adopted.
These measures improve network efficiency (96 percent for water supply and 86 percent for distribution). Globally, potable water network efficiency was approximately 74 percent in 1994 and 83 percent in 2005.
SONEDE created a progressive tariff system in the form of adjustment to usage. There have been average annual increases of about 3 percent during the last 15 years. The main advantages of this tariff system are:
Figure 1. Potable water tariffs in 2001
The water strategy was re-inforced in 2001 through different measures that aimed to address consumption:
The service rate in the rural environment peaked at 90 percent at the beginning of 2006 and has subsequently been ameliorated.
The hygiene policy generated considerable growth and provided 85 percent of the population with hygienic water supply. It was particularly marked by the coordination and management of the sector by the National Office of Cleansing (ONAS), the indexation of fees to volumes of potable water consumption and the development of the use of recycled water for agriculture.
6. The policy for agricultural water management
The irrigated sector reaches only 7 percent of the useful agricultural area in the country but it contributes in a significant way to agricultural development. It contributes 35 percent to the value of agricultural production and 20 percent to agricultural exports; it employs 20 percent of the labour force. However agriculture is a heavy consumer of available water resources. For example: 1 000 ha of irrigated area consumes the same water volume as a city of one million inhabitants with 100 litres/person.
To improve the performances of this sector, a national strategy for water economy in irrigation has been adopted. This strategy addresses the rehabilitation and modernization of irrigation systems and techniques, prioritizing irrigation demand and more autonomous management between sectors.
6.1 The decentralization of water management and the promotion of WUAs and participatory management
Currently, 970 water users' associations (WUAs) run 70 percent of the irrigated area and this will increase in future. In this context there is a need to promote participation by local women through:
6.2 Pricing irrigation water
Since 1990, a regular increase in water tariffs has been adopted which has allowed recovery of almost all costs for use and maintenance of irrigation systems. The collection of future costs will be considered in a later phase. Preferential tariffing is awarded to practices with strategic characteristics (cereals, fodder crops) and the use of recycled water for irrigation.
6.3 The water parcel programme
This programme has made considerable progress since 1995 and has been favoured with grants for irrigation equipment (40, 50, 60 percent for large, medium and small projects). Currently 75 percent of the irrigated surface is now equipped; this will reach 95 percent in 2009.
A preliminary evaluation of this programme seems encouraging. Average irrigation efficiency has increased thanks to newly introduced techniques. Agricultural yields have improved by 70 percent and there have been additional benefits.
6.4 Action for training and research
7. Lessons learned from the Tunisian experience
There is a need to integrate different components of a strategy for demand management, which has technical, economic and institutional aspects. The isolated reforms of the past accomplished few significant goals. The progressive establishment of different reforms is recommended for adoption in the local context to ensure greater involvement of the different parties concerned, particularly users and their organizations.
There is a need to balance water exportimport (physical and economic balance). The water quota per capita in Tunisia in 2004 was 417 m3/year, which is much less than the global water threshold of 950 m3/capita/year. The objective is to re-organize agricultural production to the volume of used water, either exported or imported, in the context of irrigated cultivation with enhanced additional value. Table 3 provides a chronology of water usage between 1995 and 2003.
Figure 2 allows assessment of imported and exported amounts over the given period. Average annual consumption per capita is mainly derived from local sources but also from imports. Quantities of imported water are much higher than those exported. In economic terms however the cost of 1 m3 of water exported is significantly higher than its imported counterpart according to physical availability. Thus an imbalance remains between physical and economic usage.
Figure 2. Evolution of water consumption and of the added value of the irrigation sector
Table 3. Statistical chronology of water imports/exports, 1995–2003
|Total exported (Million m3)||0.24||0.13||0.27||0.29||0.29||0.47||0.47||0.48||0.30|
|Total Imported (Million m3)||5.50||2.50||4.00||3.90||4.10||5.00||5.80||5.20||3.90|
|Positive balance (Million m3)||5.26||2.39||3.75||3.70||3.82||4.62||5.39||4.70||3.67|
1. Irrigation modernization definition
In 1997, FAO reported that there was general recognition that "irrigation modernization is a process of progressing in the technology and management of irrigation systems, combined with institutional arrangements and regulations, and its general objective is toward utilization of labour force resources, water resources, economic resources and environment resources, as well as providing services to farmers and their water distribution terms". Generally, irrigation modernization is the process of irrigation progressing with time, which implies that existing systems reform, new technologies are adopted, administrative principles are improved and good water supply services are provided through efficient utilization of labour, water, economic and environmental resources.
2. Water conservation and irrigation modernization
Water resources are not abundant in China. Average annual water availability per capita is 2 200 m3, ranking China 121st in the world. With rising population and a developing economy, demands for water are increasing, making the gap between water supply and water use much wider. Narrowing the gap, providing dependable water resources and increasing water use efficiency are important for the sustainable development of the national economy. Saving water and protecting water from pollution are included in China's current water law.
In China, agriculture water use constitutes 70 percent of total national economic water use. Irrigation, as the main agricultural water user, has low water use efficiency. Therefore, water-saving practices in irrigation areas are an important objective for irrigation modernization.
Professor Maozhi, the Chinese engineering academic, suggested that objectives for modernizing irrigation and water conservancy techniques should follow the aforementioned FAO definition of irrigation modernization in the context of the lack of environmental awareness in China. Seven basic attributes have been proposed in this regard:
3. Irrigation modernization in Shanxi
When analysing agricultural irrigation and water resources in Shanxi Province, it is plain that modernization of irrigation and water conservancy techniques can not only improve the irrigation service but also resolve
1 Taiyuan University of Technology, Taiyuan, 030024 China.
water shortages and enhance irrigation efficiency. The main components of irrigation modernization can be disaggregated as follows:
3.1 Water saving by engineering design
According to the latest research, the annual average water resource supply of Shanxi Province is 123.8 BCM. The annual average water resource per capita is 381 m3. Water availability per square kilometre of cultivated land is 2 700 m3. Shanxi Province is deficient in water supply. Water saving is therefore of the utmost importance for our future, to guarantee socio-economic development, alleviate conflict between industry and agriculture and promote the sustainable development of population, resources and the environment. No matter the location, new construction or reconstruction, water saving should be carried out via proper engineering design.
3.2 Integration of water conservancy measures
There are many types of water-saving measures that use engineering solutions (e.g. methods for preventing leakage during water transportation and distribution, irrigation methods and irrigation equipment), agricultural measures (e.g. film mulching, stubble retention management), biological measures (cropping pattern modification, seed improvement, drought-resistant varieties) and policy measures (awareness campaigns, water price regulation). The integration of different water-saving measures can enhance water-saving activities.
Most of the hydraulic engineering structures in Shanxi Province were constructed between 1950 and 1960. Due to decreasing investment, current projects in almost every irrigation district have inadequate infrastructure, which affects water transportation and distribution, resulting in water losses. Because most of the main and branch canals are earth channels, seepage control is only 49.9 percent and seepage prevention is 41.8 percent. According to the Second Water Resources Evaluation of Shanxi Province, the average canal coefficiency of the province was 0.66, field application coefficiency was 0.7 and irrigation water application coefficiency was 0.46. Therefore, it is important to introduce infrastructure to enhance irrigation efficiency, improve the water supply service and realize irrigation modernization.
3.4 Rational utilization of water resources
In Shanxi Province, annual surface water utilization approximates 2.5 billion m3 and groundwater utilization is 4 billion m3. Overexploited groundwater has reached 0.7 billion m3. Agricultural water usage is 4.2 billion m3, about 64.6 percent of total water usage, of which groundwater utilization is about 1.75 billion m3. Overexploited areas are found in Datong, Xinzhou, Taiyuan, Linfen and Yuncheng, where there are many environmental problems. Therefore, water carrying capacity must been taken into account in the course of water resource exploitation for sustainable usage.
3.5 Diversification of the investment system
Irrigation infrastructure construction involves many tasks and requires considerable funding. Market economy regulation and diversification of investment systems should be carried out to accelerate infrastructure construction. Irrigation should aim at providing services to farmers and agriculture. Therefore, during irrigation modernization, increased government responsibility, expanded government investment and structural integration are needed to diversify investment systems that should be dominated by government investment inputs. Proper laws are required on water price formulation and water tariff collection; improved education and management techniques are essential.
3.6 Mechanization of construction projects
In recent years, mechanization and semi-mechanization of construction projects, such as earthwork excavation and concrete linings for canals, have enhanced work efficiency and the development of irrigation district construction.
3.7 Establish water users' associations
The development of irrigation districts needs farmers' support and water users' associations (WUAs) should be created. Agriculture water conservancy is closely connected to farmers' livelihoods. We should insist on farmers' participation and democratic decision-making in WUA establishment according to the "Suggestion regarding enhancing the establishment of farmer water users association" issued by the Ministry of Water Resources, the State Development, Reform and Planning Committee and the Ministry of Civil Affairs.
3.8 Security of the system
The security of the system is an important component of irrigation modernization. System modernization can assure ecological security through water quality monitoring, facility maintenance and information dissemination. The irrigation district should be assigned with special safety supervisors, safety regulations, as well as warning mechanisms and emergency response modes.
3.9 Automation of system monitoring
Automation of system monitoring is an important feature of irrigation scheme management. Manual collection of data is now mostly obsolete. It is essential to adopt new technology to realize automatic data retrieval and establish a suitable information system. Automated technology can not only target plant water demand, waterheads, water quality, precipitation, evaporation, soil moisture and soil fertility, as well as flow in channels and pipes, water table levels and siltation factors, but also monitor and remotely control the operation of gates and pumping stations.
3.10 Information dissemination
Information dissemination on irrigation management is an important component to realize management of information sharing and irrigation modernization. Currently, irrigation district management and sector management mainly use traditional methods and have not accomplished effective administration and maintenance of various data or enhanced information sharing. This not only seriously affects irrigation district management but also prevents water administration departments at different levels from identifying cutting edge trends in irrigation management. Therefore, the main mission of irrigation district management is to elevate information dissemination to a higher standard.
3.11 Irrigation water supply service
The general objective of irrigation modernization is to serve farmers with regular water supply through different modern technologies. Therefore, not only good water supply infrastructure, but also fine-tuned water computation facilities are needed. Irrigation districts should have an hydraulic information feedback strategy and scheduling strategy to realize rapid water supply. Success also depends on training farmers in good irrigation and drainage practices.
3.12 Scientific evaluation system
Irrigation modernization depends on establishing modern evaluation systems that are fast and efficient. They should include scientific evaluation indices and evaluation methods to assess current situations and the potential for development in irrigation districts and further provide specific suggestions.
Irrigation modernization is a long-term effort comprising many technological and economic factors. For such modernization in China, farmers are the principal actors, the government is the overseer, the market is the foundation, technology is the facilitator, service is the root and efficiency is the objective.