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Water managed areas and irrigation


Different types of water management have been distinguished. The areas on which water, other than direct rainfall, is used for the purpose of agricultural production have been called water managed areas in the text. The term irrigation refers to that part of the water managed areas equipped to provide water to the crops and includes areas equipped for full and partial control irrigation, spate irrigation areas and equipped wetland or inland valley bottoms (Table 8).

TABLE 8 Sub-regional distribution of water management methods

Region Irrigation Flood recession cropping Water managed area
  full or partial control spate irrigation equipped wetl./ivb * total irrigation as % of total as % of cultivated
  ha ha ha ha     ha ha
Maghreb 2412900 305000 0 2717900 6 16 64 000 2781900
N-eastern Africa 5196674 196200 0 5392874 11 46 0 5392874
Arabian Peninsula 2139887 98320 0 2238207 5 80 0 2238207
Middle East 8801127 393 115164 8916684 19 30 0 8916684
Central Asia 27067534 1402448 0 28469982 59 75 1240 552 29710 34
Total Near East 45618122 2 002 361 115 164 47735647 100 48 1304552 49040199
93% 4%   97%     3% 100%
World NE as % of world   246408529

19.4%

 

* ivb = inland valley bottom

Irrigation covers 47.7 million hectares in the Near East. Central Asia represents 59% of this total, although it covers only 21% of the total area of the region. Pakistan alone, covering a little over 4% of the region, accounts for 33% of the irrigated areas. By adding Iran Turkey, Iraq and Egypt, 72% of the areas under irrigation are controlled by five of the 29 countries, covering only 25% of the Near East (Table 16).

The part of the irrigated areas in national agricultural land varies considerably between the subregions and between the countries. In the Arabian Peninsula as a whole, 80% of the cultivated area is under irrigation. In all of the seven countries within this sub-region, except Yemen, the whole cultivated area is under irrigation. In Central Asia, 75% of the cultivated area is equipped for irrigation, playing a crucial role in the production of cereals (especially wheat) and cotton. The part of the cultivated areas under irrigation is less important for the other regions as a whole, but is crucial for some countries within the regions, like Egypt and Djibouti, where the whole cultivated area is under irrigation, and Iraq, where almost 95% of the cultivated area is under irrigation (Figure 9 and Table 16). On the contrary, less than 20% of the cultivated area is under irrigation in Morocco, Algeria, Tunisia and Malta.

Full or partial control irrigation is by far the most widespread type of water management, covering 93% of the area (Table 8). In relative terms, spate irrigation is most important in the Maghreb (11% of the water managed area). In absolute terms, spate irrigation occupies by far the largest area in Pakistan, accounting for 70% of the spate irrigation in the whole Near East and 8% of the water managed area in Pakistan. Equipped wetland and inland valley bottoms (ivb) are reported only in Turkey and flood recession cropping is practiced in Pakistan (with over 94% of the flood recession cropping area of the whole region), in Mauritania (5%) and Iran (< 1%), as shown in Table 16.

In four of the 22 countries, for which information was available, (Cyprus, the United Arab Emirates, Somalia and Syria) over 80% of the irrigation potential is at present already equipped for irrigation (Figure 10 and Table 16).

Irrigation techniques

Detailed information on the irrigation techniques used in full or partial control irrigation schemes was available for only 18 out of the 29 countries and the figures below refer to these countries (Table 17). Surface irrigation is by far the most widely used technique, practiced on 87.6% of the total area. Sprinkler irrigation is practiced on 11.0% and micro-irrigation on 1.4% of the total area. In Libya and Saudi Arabia, sprinkler irrigation is by far the most predominant, while in Cyprus, Malta, Jordan and the United Arab Emirates, micro-irrigation is the most widely used technique, being practiced on over half of their full and partial control irrigation areas. In Kuwait and Lebanon sprinkler irrigation and microirrigation techniques together are practiced on more than 37% and 39% of their full and partial control irrigation area respectively. In particular the arid countries, without large rivers, choose to develop more intensively the micro-irrigation and sprinkler irrigation techniques to save water.

Origin of irrigation water

There are five possible sources of irrigation water: surface water, renewable groundwater, fossil water, treated wastewater and desalinated water. Spate irrigation areas, equipped wetland and flood recession cropping areas are all irrigated by surface water. Table 9 shows the origin of irrigation water for the full or partial control irrigation equipped areas.

It was not possible to make a distinction between renewable and non-renewable groundwater use, but a large part of the groundwater used is fossil water, especially in the more arid sub-regions and countries. For the Near East as a whole the origin of irrigation water consists mainly of surface water, but there are significant differences between the sub-regions. The large contribution of surface water in North-eastern Africa and the Middle East reflects the fact that these regions' hydrology is dominated by the presence of large rivers: the Nile, the Euphrates and the Tigris. The Indus, the Amu Darya and Syr Darya are also important for irrigation in Pakistan, Kyrgyzstan, Tajikistan and Turkmenistan. In Iran and, to a lesser extent, Pakistan groundwater also plays an important role. The contribution of groundwater is most important in the Arabian Peninsula, where there are no big rivers. Non-conventional water for irrigation is used in 10 countries (Table 18) and plays a fairly important role in the drier regions of the Maghreb, the Arabian Peninsula and on the island of Malta. It consists mostly of treated wastewater (in Morocco untreated wastewater is also used in very specific conditions). In Kuwait, 1 180 ha are irrigated by treated wastewater and about 680 ha in greenhouses are irrigated by desalinated water. In general, desalinated water is still too saline for irrigation purposes. In Kuwait, 39% of the irrigated area is irrigated by non-conventional water, in Malta 37% and in Bahrain 14%. In all the other countries less than 6% is irrigated in this way (Table 18).

TABLE 9 - Origin of irrigation water by sub-region

Region Full or partial control irrigation: area equipped in hectares
surface water % of total groundwater (renewable and fossil) % of total non- conventional water % of total total area
Maghreb 1037649 43.0 1355251 56.2 20000 0.8 2412900
North-eastern Africa 4969800 95.6 222674 4.3 4200 0.1 5196674
Arabian Peninsula 51000 2.4 2066874 96.6 22013 1.0 2139887
Middle East 7198091 81.8 1598856 18.2 4180 (-) 801127
Central Asia 17865132 66.0 9202402 34.0 0 0.0 27067534
Total 31121672 68.2 14446057 31.7 50393 0.1 45618122

Note: Figures for Algeria, Libya, Somalia and Turkmenistan have been estimated on the basis of sub-regional trends


Indicators of irrigation intensity


Two indicators are frequently used to assess irrigation intensity: the rate of use of land equipped for irrigation, which is that part of the equipped area actually used for production at least once a year, and the cropping intensity, which is the ratio between irrigated crops areas (where double or triple cropping areas are counted twice or three times respectively) and the physical areas equipped for irrigation.

The survey showed that in general these figures were either not available or not reliable at country level. Moreover, in most cases in the literature it was not possible to distinguish between these two indicators. It is possible, for example, that part of the equipped area was not used for several reasons (abandoned, water shortage, etc.), while the remaining part was cultivated in double or triple cropping. Moreover, figures vary significantly from one year to another, particularly in the areas where irrigation schemes are facing water availability problems.

Table 17 shows the part of the full and partial control irrigation equipped area which is actually irrigated for the 19 countries for which the information was available. In all countries the rate of use of the equipped area was greater than 50%: in three countries it was less than 60%, in six countries it was reported to be 100%. Overall, the equipped area of these 19 countries represents 23.8 million hectares (52% of the equipped area of the whole region). Of these 23.8 million hectares about 3.8 million hectares, or 16%, are not irrigated.

It was also difficult to get reliable information on cropping intensity for the reasons explained above. Figures available for some countries show a cropping intensity of 1.66 for Egypt, 1.19 for Syria, 1.15 for Oman (all referring to 1993) and 1.07 for Jordan (in 1991). In Saudi Arabia, Bahrain and Kuwait the cropping intensity is reported to be 1, probably because no cropping is possible in the hot season. In Malta, 95% of the equipped area was irrigated in 1990, with a cropping intensity on that area of 2.50. In Cyprus it was 0.85 in 1994 and in Qatar only 0.66 in 1993 because of water shortages.


Irrigated crops


The figures on irrigated crops are very incomplete and do not allow the establishment of statistical tables by country showing the distribution of the major crops under irrigation in the Near East. However, by using all the data available, information can be obtained for about 35.8 million hectares. The results are summarized in Table 10, in which the different crops have been grouped into seven major categories.

TABLE 10

Sub-regional distribution of the main irrigated crops (based on partial information)

Region (unit: '000 ha) wheat other cereals * fodder crops vegetables

**

cotton other annual *** permanent crops total
Maghreb 158 507 125 573 16 179 464 2 022
8% 25% 6% 28% 1% 9% 23% 100%
N-eastern Africa 1077 2024 1098 409 704 858 386 6556
16% 31% 17% 6% 11% 13% 6% 100%
Arabian Peninsula 916 243 323 178 13 23 326 2 022
45% 12% 16% 9% 1 % 1% 16% 100%
Middle East 784 576 38 307 408 396 197 2706
29% 21 % 1 % 11 % 15% 15% 7% 100%
Central Asia 10331 3769 1187 896 3846 846 1615 22490
46% 17% 5% 4% 17% 4% 7% 100%
Total Near East 13226 7119 2771 2363 4987 2302 2988 35796
37% 20% 8% 7% 14% 6% 8% 100%

* total includes 3 449 000 ha rice, 1143000 ha maize, 945000 ha barley and 568000 ha sorghum
** total includes 225 000 ha tubers (mainly potatoes) and 374 000 ha pulses
*** total includes 386 000 ha sugar cane, 286 000 ha oil crops (exe. olives) and 168 000 ha sugar beet

The most widespread crop is wheat, which represents 37% of the cropped area. It is the most important irrigated crop in Central Asia, the Arabian Peninsula and the Middle East. The largest rice area is in Central Asia (mainly in Pakistan and Iran) and in Egypt (the Nile Delta area). The whole category of irrigated cereals is predominant in each sub-region and represents 57% of the irrigated crops in the whole region, varying between 33 % in the Maghreb and 63 % in Central Asia. Irrigated cereals are present in each country, except in Bahrain and Malta.

Irrigated fodder crops are important in Egypt, where berseem represents over 20% of the cropped area, and are present in each single country of the Arabian Peninsula, occupying between 12% (Saudi Arabia) and 32% (Qatar) of the cropped area. In Kyrgyzstan fodder crops represent 37 % of the irrigated cropped area.

Vegetables are present in all regions and almost every single country. They are the most important irrigated crops in the Maghreb, representing 28% of the total cropped area under irrigation.

In absolute and relative terms, cotton is an important irrigated crop in Central Asia, covering over 3.8 million hectares. It is also a relatively important crop in Egypt, Sudan, Syria and Turkey. Sugar cane is mainly found in North-eastern Africa, Morocco and Iran.

Permanent crops under irrigation (dates, citrus, other fruits, olives) are present in almost all countries of the Maghreb, North-eastern Africa, the Arabian Peninsula and the Middle East. In relative terms, there is the largest concentration in the Maghreb, occupying 23% of the irrigated area, followed by the Arabian Peninsula with 19%. In Bahrain, Oman and the United Arab Emirates they represent over 50% of the total irrigated cropped area. In Cyprus, Jordan and Lebanon they represent around 40% of the irrigated area. In absolute terms the largest area of permanent crops under irrigation is in Iran, occupying almost 1.6 million hectares, which represents 22% of the irrigated cropped area of the country and 53% of the irrigated permanent crop area in the entire Near East.


Salinization, drainage and environment


Arid areas are sensitive to salinization problems because the volume of rainwater dissolving the salts generated by the soil is low. By extracting water from the soil, evaporation and evapotranspiration tend to increase salt concentrations. Direct evaporation from the soil surface causes a rapid accumulation of salt in the top layers. When significant amounts of water are provided by irrigation with no adequate provision for leaching of salts, the soils rapidly become salty and unproductive. Water storage in the reservoirs, where evaporation is intense, tends to increase the salt concentration of the stored water. For all these reasons, the Near East is a region subject to salinization and the problem has been known and recognized for a long time. However, assessment of salinization at national level is a difficult enterprise and very little information on the subject could be found during the survey. Furthermore, no commonly agreed methods exist to assess the degree of irrigation-induced salinization. Figures on areas salinized by irrigation were available for only eight of the 29 countries (Table 19). In the near future, more information on salinization will probably become available and strategies to improve the situation should be defined, as this has been recognized as a priority by most of the Near East countries. On average around 29% of the irrigated areas in the eight countries are reported as having salinization problems, varying from 3.5% in Jordan to over 85 % in Kuwait.

One of the measures necessary to prevent irrigation-induced waterlogging and salinization in arid and semi-arid regions is the installation of drainage facilities. Drainage, in combination with adequate irrigation scheduling, allows for the leaching of excess salts from the plant root zone. Figures on drained areas are available for 13 of the 29 countries (Table 16). About 34% of the irrigated areas in these countries have been provided with drainage facilities, varying from 0.6% in Iran to over 90% in Egypt.

Over-extraction of groundwater leads to a lowering of the groundwater table and a deterioration of the groundwater quality due to sea water intrusion and/or the upward diffusion of deeper saline water. Using saline groundwater for irrigation may increase soil salinity. All the countries of the Arabian Peninsula are facing this problem as are the islands of Cyprus and Malta and the coastal zones of countries like Libya and Egypt. Also in Tunisia and Djibouti the groundwater used for irrigation is reported to be rather saline.

The Aral Sea basin

The Aral Sea is not included in the Near East Region. However, since most of the countries of the Aral Sea basin are part of the Near East Region, special attention has been paid to the Aral Sea basin, in view of its particular environmental problems related to water resources and irrigation. Due to the increasing need for water for irrigation in the Aral Sea basin, mainly from the 1950s onwards, the sea level continually fell as more water was diverted from its two major effluents, the Amu Darya and the Syr Darya. Between 1960 and 1965, its surface area shrank by more than half, from 64 500 kmē to less than 30 000 kmē. At the same time, the level fell by 19 metres and its salinity tripled. Once the world's fourth largest lake, the Aral Sea has now lost so much of its water volume that what remains is contained in three separate highly saline lakes. The dry seabed exposed to weathering has increased soil salinization and desertification around the sea. It is estimated that since the 1970s dust storms yearly spread tens of millions of tons of dust and salt, polluted with pesticides, over the whole region. Traces have been found at a distance of more than 1 000 kilometres. Waterlogging is reported in large areas due to inefficient irrigation combined with insufficient or no drainage. In 1993, all five Aral Sea basin countries (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan) signed an agreement to improve the situation in the basin, but so far progress has been slow due to the region's political and economic situation.


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