|Pays, régions, bassins fluviaux|
|Ressources en eau|
|Usages de l'eau|
|Irrigation et drainage|
|Ensembles de données|
|Cartes et données spatiales|
Info pour les médias
|Visualisations et infographies|
|ODD Cible 6.4|
Ten years after the first publication on the Southern and Eastern Asia region, it appeared necessary to update the data and to identify the main changes in water use and irrigation that had occurred there. The countries forming the region were determined by the regional distribution given in FAO's Water Report 23 "Review of world water resources by country" (2003). In that report the world was divided into ten large regions as shown in Figure 3.
The 22 Southern and Eastern Asia countries have been grouped into four subregions, based on geographical and climatic homogeneity, which has a direct influence on irrigation. These subregions (Figure 4) and the countries they include are:
The previous survey (FAO, 1999) distinguished five subregions, including the Far East and Eastern Asia. The Far East was composed of two countries: Japan and the Republic of Korea. The present survey does not include Japan and the Republic of Korea has been included in East Asia, which thus replaces the Far East and Eastern Asia subregions of the previous survey. South Asia is the same as the Indian Subcontinent in the previous survey, but with the addition of Pakistan, which in the previous survey was included in the Near East region (FAO, 1997a). Mainland Southeast Asia is exactly the same as the Southeast subregion in the previous survey. Maritime Southeast Asia is the same as the Islands subregion in the previous survey, but now includes Timor-Leste, which at the time of the preparation of the previous survey was not yet an independent country.
This regional overview presents distinguishing features arising from the new data collected on a national scale for issues addressed in the twenty two country profiles and the four transboundary river basin profiles in the region. The interest of this new survey lies in the updating of data and in the trends during the last ten years.
|River Basin profile:|
|Presentation of the study|
|Geography, climate and population|
|Economy, agriculture and food security|
|Irrigation and water management|
|Cultivation in full control irrigation schemes|
|Trends in the last ten years|
|Legislative and institutional framework of water management|
|Environment and health|
|Prospects for agricultural water management|
|Main sources of general information|
To the two objectives of the previous publication (FAO, 1999) a third has been added in this new survey of Southern and Eastern Asia:
To obtain the most reliable information possible, the survey is organized as follows:
Where possible, AQUASTAT has made use of national capacity and competence. While collecting the information by country, preference was given to national experts as they have a better knowledge of their own country and easier access to national or so-called ‘grey’ documents, which are not available outside the country. The choice of the countries for which a national consultant was recruited depended on several factors, namely: the importance of irrigation in the country; the availability of an expert; the scarcity of data observed during the previous survey; and the funds available. For about half of the countries concerned, a national consultant assisted the AQUASTAT team or direct assistance was provided by government institutions, national research institutions and/or universities.
Country and river basin profilesCountry profiles
Country profiles are prepared in English, which is the FAO official language in most of the countries of the Southern and Eastern Asia region. They describe the state of water resources and water use in the respective countries, as well as the state of agricultural water management. The aims are to describe the particularities of each country and the problems met in the development of the water resources and, in particular, irrigation. They summarize the irrigation trends in the country and the prospects for water management in agriculture as described in the literature. The country profiles have been standardized and organized in the following sections:
Standardized tables are used for each country. A hyphen (-) indicates that no information is available. As most information is available only for a limited number of years, the tables present the most recent reliable information and indicate the year to which it refers. In the online AQUASTAT country database, however, all available information is accessible.
The information in the country profiles is much more detailed than that in the previous AQUASTAT survey of the region. In order to establish a more complete picture of the agricultural water sector in each country, it addresses issues related to water and to irrigation that were not previously included. Some issues have been added in response to user demand.River basin profiles
In addition to country profiles, profiles have been prepared of four transboundary river basins in the region: the Ganges-Brahmaputra-Meghna, Indus, Mekong and Salween river basins. The major aims are to describe transboundary water issues and to provide a chronology of major events in the basins. The sections are organized as follows:
Data collection, processing and reliability
The main sources of information were:
Furthermore, the following sources systematically provide certain data:
In total, more than 50 variables have been selected and these are presented in the national tables attached to the respective country profiles. They are standardized and ordered in categories corresponding to the various sections of the profile: characteristics of the country and population; water: resources and use; and irrigation and drainage. See the online glossary for the definitions of the variables. Additional tables have been added to the country profiles where information is available, especially in order to specify regional or river basin data.
In most cases, a critical analysis of the information is required in order to ensure the general coherence of information collected for a given country. Where several sources result in divergent or contradictory information, preference is given to information collected at national or sub-national level rather than at regional or world level. Moreover, except in the case of evident errors, official sources are privileged. As regards shared water resources, the comparison of information between countries has made it possible to verify and complete the data concerning the flows of transboundary rivers and to ensure coherence at a river basin level. This information has been added more in detail in the country water resources sheets, which can be accessed from the water resources page.
In spite of these precautions, the accuracy, reliability and frequency with which information is collected vary considerably according to the region, the country and the category of information. These considerations are discussed in the profiles.
The regional analysis tables show the period 1999–2009 as the period between the two surveys. The AQUASTAT team justifies this choice by virtue of the slow evolution of data for different years for each country. However, should more precision be required, the summary tables and the online database specify the exact year for the items of national data.
GEOGRAPHY, CLIMATE AND POPULATION
The total area of Southern and Eastern Asia is 20.8 million km2, or 15 percent of the world’s emerged landmass (Table 1, Table 39). Out of the 22 countries in the region, China represents 46 percent and India 16 percent of the total area, the two countries together occupying almost two-thirds of the total area of the region (Table 29). The smallest six countries - Maldives, Brunei Darussalam, Timor-Leste, Bhutan, Sri Lanka and Republic of Korea - together comprise barely 1 percent of the total area. The cultivated area is estimated at 442 million ha (Table 1). In South Asia almost half of the total area of the subregion is cultivated going down to just over 10 percent in East Asia. Considering the cultivable area, however, in all regions more than three-quarters of the cultivable area is already cultivated. In some countries, the entire cultivable area seems to be already cultivated. However, the definition of cultivable varies from country-to-country, for example one may or may not include the area under permanent pasture in the figure of cultivable.
Average annual precipitation is estimated at 1 136 mm for the region. It varies from less than 100 mm in parts of western China and southern Mongolia to as high as 8 000 mm in the mountain areas of Papua New Guinea and more than 10 000 mm in the Khasi hills in northeast India (Figure 5).
Total population was estimated at 3 605 million inhabitants in 2009, representing about 53 percent of the world’s population (Table 2, Table 39). China and India are the most and the second most populous countries in the world respectively, together accounting for about 38 percent of the world’s population and 71 percent of the Southern and Eastern Asia region population (Table 30). Population density in the region is 173 inhabitants/km2, compared to 51 inhabitants/km2 for the world as a whole and 33 inhabitants/km2 for Africa, varying from less than two inhabitants/km2 in Mongolia to more than 1 000 inhabitants/km2 in Bangladesh and Maldives (Figure 6 and Table 30). The annual demographic growth rate in the region was estimated at 0.98 percent for the period 2008-2009, compared to 1.16 percent for the whole world.
The population of Southern and Eastern Asia is predominantly rural: about 61 percent of the total population is rural, similar to Africa, compared to 50 percent for the world as a whole. Though, rural population varies from more than 80 percent in Nepal, Papua New Guinea and Sri Lanka to less than 30 percent in Brunei Darussalam and Malaysia and even less than 20 percent in the Republic of Korea. Also the percentage of the economically active population engaged in agriculture is, with about 56 percent, high compared to 40 percent for the world.
In 2008, around 12 percent of the total population of Southern and Eastern Asia, 17 percent of the rural population and 4 percent of the urban population, had no access to safe drinking water. In 2010, average life expectancy was 69 years.
The East Asia subregion includes China, Democratic People’s Republic of Korea, Mongolia and the Republic of Korea. It extends over 11.4 million km2, which is about 55 percent of the total area covered by this survey and 8.5 percent of the world area (Figure 1 and Table 2). China covers 84 percent of the area of this subregion. The subregion is bordered to the north by Mongolia and the Russian Federation, to the east by the Pacific Ocean, to the south by Viet Nam, Lao People’s Democratic Republic, Myanmar, India, Bhutan and Nepal, and to the west by Pakistan, Tajikistan, Kyrgyzstan and Kazakhstan. This region is mainly mountainous with about 80 percent of the landmass lying above the mean altitude of 1 000 m above sea level. In 2009 about 130 million ha was cultivated.
Apart from east and south China, where the climate is determined by the monsoon, the region is generally characterized by long cold winters (September/October to April/May) caused by the north and northwest winds from Siberia with temperatures ranging from -20 °C to -40 °C. Precipitation is more important in the summer months, from May/June to August/September. Large parts of south Mongolia and central China suffer from a very arid climate and are facing severe water scarcity problems.
Average annual precipitation in the subregion is 599 mm, varying from less than 25 mm in the Tarim and Qaidam basins in western China to an average of 1 274 mm in the Republic of Korea (Table 31). Among the factors affecting agricultural production in the region are low soil moisture and air humidity in spring and early summer, and frosts in spring and autumn.
Total population was 1 441 million inhabitants in 2009, or 40 percent of the region, with China accounting for almost 95 percent of this total. About 52 percent of the population lives in rural areas, varying from 54 percent in China to 17 percent in the Republic of Korea (Table 2). The average population density of the subregion is 127 inhabitants/km2, ranging from less than 2 inhabitants/km2 in Mongolia to 480 inhabitants/km2 in Republic of Korea. Annual population growth ranges from 0.5 percent in Republic of Korea to 1.3 percent in Mongolia during the period 1999-2009, with a subregional average annual growth of 0.6 percent, while in the previous decade (1989-1999) it was estimated at 1.0 percent.
The South Asia subregion, comprising Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka, covers about 4.5 million km2, or 22 percent of the Southern and Eastern Asia region (Table 2). India covers 73 percent of the area of this subregion. The subregion is bordered to the north by China, to the east by Myanmar and the Bay of Bengal, to the south by the Indian Ocean, to the west by the Arabian Sea and the Islamic Republic of Iran, and to the northwest by Afghanistan. The geomorphology of these countries consists of a large portion of floodplains along the Indus and Ganges river basins, some terraces and hilly areas, and the mountainous terrain of the Himalayas, with the world’s highest peak, Mount Everest at 8 848 m, located in the Nepal Himalayas. The cultivable area is 219 million ha, 83 percent of which is in India, and in 2009 about 204 million ha was cultivated, or 93 percent of the cultivable area.
The subregion experiences a tropical monsoon climate, with significant seasonal variations in rainfall and temperature. About 80 percent of the total precipitation occurs during the monsoon period. The climatic year includes two monsoon periods: the southwest monsoon (June-September) concentrating most of the rainfall, and the northeast monsoon (November-March), which has relatively light rainfall compared to the southwest monsoon. The highest temperatures are registered during the dry season (generally from March to May) with 43 °C in Bangladesh and 40 °C in the northwest regions of India.
Average annual precipitation in the subregion is about 1 114 mm, varying from less than 150 mm in the northwest desert of Rajasthan in India, to more than 10 000 mm in the Khasi hills in northeast India.
Total population was 1 576 million in 2009, or 44 percent of the region, of which 77 percent lives in India, 11 percent in Pakistan and 9 percent in Bangladesh. About 70 percent of the population lives in rural areas ranging from 82 percent in Nepal to 61 percent in Maldives (Table 2 and Table 30). The average population density in the subregion, 352 inhabitants/km2, is more than twice the average density of the region as a whole and more than seven times the population density of the world. National average densities range from 1 040 inhabitants/km2 in Maldives and 1 021 inhabitants/km2 in Bangladesh, which is amongst the highest density in the world, to 19 inhabitants/km2 in Bhutan. Annual population growth ranges from 1.5 percent in Sri Lanka to 2.6 percent in Bhutan during the period 1999-2009, with a subregional average annual growth of 1.6 percent, while in the previous decade (1989-1999) it was estimated at 1.8 percent.
Mainland Southeast Asia
The Mainland Southeast Asia subregion with an area of 1.9 million km2, or 9 percent of the total area of the region, is composed of Myanmar and the four riparian countries of the lower Mekong basin: Cambodia, Lao People’s Democratic Republic, Thailand and Viet Nam (Table 2). Myanmar and Thailand cover 35 percent and 26 percent of the area of this subregion respectively (Table 29). The subregion is bordered to the north by China, to the east by the South China Sea, to the south by the Gulf of Thailand, to the west by the Indian Ocean, the Andaman Sea and the Bay of Bengal, and to the northwest by Bangladesh and India. Mountains and hills are the main physiographical features, covering about two-thirds of the total area, with the highest point situated at 5 800 m above sea level in the extreme north of Myanmar. The extensive plains along the Mekong, Red and Ayeyarwady rivers are frequently subject to flooding. The cultivable area is 61 million ha, 44 percent of which is in Thailand, and in 2009 about 46 million ha was cultivated, or 76 percent of the cultivable area.
The climate is mainly governed by the alternance between the wet season, characterized by the southwest monsoon (May to October) with heavy rainfall, and the dry season, characterized by the northeast monsoon (November to February) which is relatively cool and dry. About 75 percent of the total rainfall occurs during the wet season. This results in a large difference in the water level in rivers between the wet and the dry seasons: the water level in the Mekong river may differ by up to 20 m between the two seasons. The average annual rainfall in the region is 1 825 mm, ranging from 500 mm in the central dry zone in Myanmar and 650 mm in Phan Rang in Viet Nam to more than 4 000 mm in the mountains of Rakhine in Myanmar and Bac Quang in Viet Nam.
In 2009, the total population was 223 million inhabitants, or 6 percent of the region, with Viet Nam and Thailand together accounting for almost 70 percent of this total (Table 30). About 69 percent of the population lives in rural areas, varying from 80 percent in Cambodia to 66 percent in Thailand (Table 2). The average population density of the subregion is 115 inhabitants/km2, ranging from 26 inhabitants/km2 in Lao People’s Democratic Republic to 263 inhabitants/km2 in Viet Nam, but going up to more than 1 000 inhabitants/km2 in the Red River Delta in Viet Nam. Annual population growth ranges from 0.7 percent in Myanmar to 1.6 percent in Lao People’s Democratic Republic during the period 1999-2009, with a subregional average annual growth of 1.0 percent, while in the previous decade (1989-1999) it was estimated at 1.4 percent.
Maritime Southeast Asia
This subregion includes the countries of the Indian and North Pacific oceans, characterized by their insular nature: Brunei Darussalam, Indonesia, Malaysia, Papua New Guinea, Philippines and Timor-Leste. Its land area extends over 3 million km2, which is about 14 percent of the total area under this survey (Table 2). Indonesia covers 63 percent of the area of this subregion (Table 30). The relief is dominated by extensive lowland plains and swamps, which contrast sharply with high mountain ranges, with the highest point situated at 5 030 m above sea level in the volcanic mountains of Indonesia. In 2009 about 62 million ha was cultivated.
The climate of this subregion is tropical and monsoonal, characterized by the uniformity of temperature, 27 °C throughout the year, and high humidity, varying from 70 to 80 percent. The region is under the influence of two main air streams: the northeast monsoon, blowing from October to March, and responsible for heavy rainfall, and the southwest monsoon occurring between May and September. Many islands of the region are liable to extensive flooding and typhoon damage during a period extending from June to September. The average rainfall in this region is 2 747 mm, ranging from less than 1 000 mm in Port Moresby in southeast Papua New Guinea to more than 8 000 mm in some mountainous areas in the same country (Table 31).
Total population was 365 million inhabitants in 2009, or 10 percent of the region, with Indonesia accounting for 65 percent of this total (Table 30). The population is unevenly distributed and is mainly concentrated along the coastal areas. About 53 percent of the population lives in rural areas, varying from 25 percent in Brunei Darussalam to 87 percent in Papua New Guinea (Table 2). The average population density of the subregion is 121 inhabitants/km2, ranging from 14 inhabitants/km2 in Papua New Guinea to 306 inhabitants/km2 in the Philippines. Annual population growth ranges from 1.2 percent in Indonesia to 2.9 percent in Timor-Leste during the period 1999-2009, with a subregional average annual growth of 1.5 percent, while in the previous decade (1989-1999) it was estimated at 1.6 percent.
ECONOMY, AGRICULTURE AND FOOD SECURITY
The economy of the Southern and Eastern Asia region is dominated by agriculture, though industry and services are becoming more important. The sum of national GDPs in 2009 amounted to US$8 725 096 million, which is 15 percent of world GDP. It corresponds to a GDP of about US$2 420/inhabitant, ranging from US$426/inhabitant in Nepal to US$29 262/inhabitant in Brunei Darussalam. Based on the Human Development Index (HDI) where 0 = lowest and 1 = highest, in 2010 the countries rank between the 89th and the 138th place out of a total of 169 countries, except for Republic of Korea, Brunei Darussalam and Malaysia which hold the 12th, 37th, and 57th place with an HDI of 0.877, 0.805 and 0.744 respectively. The HDI for Bhutan and Democratic People’s Republic of Korea is unknown (Table 30).
Although Asia’s economy is predominantly agricultural, regions have developed industrially where power facilities, trained labour, modern transport and access to raw materials are available. China, India and the Republic of Korea are making considerable progress. Also petroleum is contributing greatly to the income of some countries such as Malaysia, Thailand and Indonesia, manganese in India and chromites in the Philippines. China produces great amounts of tungsten, antimony, coal, and oil (Columbia University, 2007).
In 2009, the added value of the primary sector (agriculture) contributed 11.6 percent to the GDP of the Southern and Eastern Asia region. It ranged from 0.7 percent in Brunei Darussalam (2006) and 2.6 percent in the Republic of Korea (2009), to 35.9 percent in Papua New Guinea (2009) and 48.4 percent in Myanmar (2004). An average of 56 percent of the economically active population is engaged in the farming sector (Table 2 and Table 30). It ranges from 0.5 percent in Brunei Darussalam, 5.9 percent in Republic of Korea and 13.8 percent in Malaysia to 80 percent in Timor-Leste, 92.8 percent in Bhutan and 93 percent in Nepal. Mainland Southeast Asia is the subregion with most economically active people involved in agriculture, accounting for 61 percent, followed by East Asia with 60 percent, South Asia with 53 percent and Maritime Southeast Asia with 39 percent.
The cultivated area per person economically active in agriculture varies from a low 0.2 ha/person in Nepal, Bangladesh and China to 3.9 ha/person in Mongolia, 4.6 ha/person in Malaysia and 8 ha/person in Brunei Darussalam, giving an average for the region of 0.4 ha/person (Table 29).
Rice, by far the most important food crop, is grown for local consumption in the heavily populated countries (China, India, Indonesia and Bangladesh), while countries with smaller populations (Thailand, Viet Nam and Pakistan) are generally rice exporters. Other important crops are wheat, soybeans, peanuts, sugarcane, cotton, jute, silk, rubber, tea and coconuts.
Renewable water resources (primary freshwater)
Compilation of information on water resources shows large methodological discrepancies between countries. This survey distinguishes between internal renewable water resources (IRWR) and total renewable water resources (TRWR). IRWR is that part of a country’s water resources generated from endogenous precipitation. It is computed by summing surface water flow and groundwater recharge and subtracting their common part. The computation of TRWR is made by summing IRWR and external flow. It is a measure of the maximum theoretical amount of water available to a country without any considerations of a technical, economic or environmental nature. The methodology used in the survey also distinguishes between natural and actual external flow: natural flow is the average annual amount of water that would flow at a given point in a river without any human influence, while actual flow takes into account volumes of water reserved by treaties and, depending on the information available, may or may not consider the reduction of flow caused by upstream withdrawal.
The large range of climates encountered in the region generates a variety of hydrological regimes. The region is host to some of the most humid climates (with annual precipitation above 10 000 mm in some places) giving rise to major rivers, while in other parts the climate is very arid with closed hydrologic systems. As a result, the region shows a very uneven distribution of its water resources and of its water-use conditions. In the humid areas, water management concerns have mostly been dominated by considerations related to flood control. This is the case in the Brahmaputra, Ganges, Indus and Mekong basins. In the arid areas, such as in central China, where water is scarce, hydrological studies have been oriented much more towards water resources assessment.
The hydrology of the region is dominated by the typical monsoon climate, which induces large inter-seasonal variations of river flows. In this situation, average annual values of river flows are a poor indicator of the amount of water resources available for use. In the absence of flow regulation, most of the water flows during a short season when it is usually less needed. A fair estimate of water resources available for use to a country should include figures of dry season low flow. However, such information is available only for a few countries: in Bangladesh, the surface flow of the driest month represents only 18 percent of the annual average; in Indonesia, it is 17 percent. In India, the flow distribution of selected rivers in the monsoon period represents 75-95 percent of the total annual flow. In north China, 70-80 percent of the annual runoff is concentrated in the rainy season. Given the seasonal nature of the Himalayan runoff, roughly 85 percent of the annual flow in the Indus in Pakistan is in the summer (kharif season). As a first approximation, one could then state that in the absence of storage the amount of water readily available for use is between 10 and 20 percent of the total renewable water resources.
The information collected from the countries of the region does not make it possible to distinguish between actual and natural flow of the major rivers, i.e. the impact of irrigation and other water withdrawal on the runoff. In this survey, figures were systematically considered as natural flow, while also taking into consideration possible treaties. This option of course may lead to an underestimation of natural flow in some cases. At least in one case, the Ganges river, the withdrawals in the upstream country (India), are known to affect significantly the volumes of water available to the downstream country (Bangladesh). This has led to a treaty between the two countries on agreed procedures for the management of the river flow. A treaty also exists between India and Pakistan referring to the rivers in the Indus river basin (see river basin and country profiles). In view of the hydrological regime of the rivers in the region, it can be assumed that runoff in the countries of South Asia and Mainland and Maritime Southeast Asia is not significantly affected by withdrawals, while the difference between natural and actual flow may be much more important in the arid regions in East Asia (mostly China).
Overall, the region is relatively well endowed with water resources: for a total area representing 16 percent of the world’s land surface, it receives 22 percent of its precipitation and produces 25 percent of its water resources. However, as the region is home to 53 percent of the world’s population, the amount of water resources per inhabitant is 2 970 m3/year, which is less than half the world’s average of 6 236 m3/year in 2009 (Table 39).
The volume of annual precipitation in Southern and Eastern Asia is estimated at about 23 646 km3. This volume is equal to a regional average depth of 1 136 mm, compared to a global average of 804 mm, but with significant disparities between countries (Table 3 and Figure 5). Average annual precipitation varies from less than 25 mm in western China to more than 10 000 mm in northeast India. At country-level, the driest country is Mongolia with 241 mm/year on average, followed by Pakistan with 494 mm and China with 645 mm. Papua New Guinea is the rainiest country with, on average, 3 142 mm/year, followed by Malaysia with 2 875 mm, Brunei Darussalam with 2 722 mm and Indonesia with 2 702 mm (Table 31). The driest subregion is East Asia with an annual average of 599 mm, while South Asia receives 1 114 mm, Mainland Southeast Asia 1 825 mm and Maritime Southeast Asia 2 747 mm.
Annual renewable water resources in Southern and Eastern Asia account for 10 707 km3 (Table 3 and Table 31). In absolute terms China accounts for the largest amount of water resources, 2 812 km3/year or 26 percent of the region’s water resources, but this refers to 46 percent of the region’s total area. Indonesia follows with 2 018 km3, or 19 percent of the water resources of the region, which contrary to China is an important value taking into account that the country represents only 9 percent of the total area of the region. India accounts for 1 446 km3/year (Table 31 and Figure 7). As for the subregions, Maritime Southeast Asia accounts for 36 percent of the renewable water resources of the region with only 15 percent of the total area of the region. On the other hand, East Asia accounts for 28 percent of the total water resources for an area equivalent to 55 percent of the region. South Asia and Mainland Southeast Asia account both for 18 percent of the total water resources, for an area equivalent to 22 percent and 9 percent respectively (Figure 2).
Population has increased by almost 25 percent since the previous survey, resulting in a decrease in average annual internal renewable water resources (IRWR) per inhabitant from about 3 455 m3 in 1999 to 2 970 m3 in 2009. This is less than half of the global average IRWR/habitant of 6 236 m3, and ranges from 96 m3 in Maldives, 323 m3 in Pakistan and 714 m3 in Bangladesh to 31 155 m3 in Lao People’s Democratic Republic, 109 224 m3 in Bhutan and 119 499 m3 in Papua New Guinea (Table 31 and Table 39). The distribution of total actual renewable water resources (TARWR) is different because of transboundary river basins, for example in Cambodia the IRWR are 8 626 m3/inhabitant while the TARWR are almost four times as high, 34 061 m3/inhabitant, and in Lao People’s Democratic Republic these figures are 31 155 m3 and 54 573 m3 respectively. Maritime Southeast Asia is the sub-region with the highest IRWR per inhabitant, 10 644 m3, followed by Mainland Southeast Asia with 8 499 m3/inhabitant, East Asia with 2 068 m3/inhabitant and South Asia with 1 228 m3/inhabitant.
Table 4 presents those countries with IRWR less than 1 700 m3/inhabitant, which is considered to be a threshold below which there are indications of water stress. Looking at TARWR, all of them except the island Maldives have higher TARWR because they have a relatively large proportion of external renewable water resources. However, except for Bangladesh the situation remains the same, meaning that the TARWR are also less than 1 700 m3/inhabitant and slowly they are even approaching a situation of chronic water scarcity (threshold 1 000 m3/inhabitant per year) (Table 3 and Figure 8).
Other sources of water
Water scarcity forces national economies to find alternative ways to satisfy the demand for water. Other sources of water might include the following:
No information is available on the use of fossil groundwater. Twelve of the 22 countries mention overexploitation of renewable groundwater resources, meaning that the withdrawal is larger than the recharge, which leads to problems such as lowering of the groundwater tables, saltwater intrusion, groundwater pollution, etc. (see the chapter on water withdrawal).
Figures for direct use of treated wastewater are available only for 2 out of 22 countries of the region and are often underestimates. China and Viet Nam report 13 390 million m3/year and 175 million m3/year respectively. Even produced and treated wastewater data are available for only 9 countries, of which for 5 countries the latest information is 15-20 years old (Table 5).
Total use of desalinated water in the region is estimated to be 36 million m3/year. However, only 6 countries report on this source of water. Of these, Indonesia is by far the largest user of desalinated water, accounting for 52 percent of the region’s total, followed by China and Malaysia with 30 and 12 percent respectively. In Maldives, being a small country, desalination has a notably importance amounting to 1.2 million m3, which represents 20 percent of its total water withdrawal. India and the Republic of Korea desalination amounts to only 0.6 and 0.2 million m3/year (Table 33).
Total dam capacity in the Southern and Eastern Asia region is 1 048 km3, of which 75 percent is located in just two countries: China (54 percent) and India (21 percent) (Table 6). Thirty-nine dams in the Southern and Eastern Asia region have a capacity over 5 km3, of which seventeen in China, ten in India, five in Thailand, two in Malaysia, two in Pakistan, one in Bangladesh, one in Lao People’s Democratic Republic and one in Viet Nam. In total these thirty-nine large dams account for 470 km3, or 45 percent of the total dam capacity in the Southern and Eastern Asia region. The dam with the largest capacity (39 km3) is the Three Gorges Dam in China, completed in 2006, which is considered to be the largest hydropower project in the world. The Longtan and Longyangxia dams, both also in China, follow with a capacity of 27 km3 and 25 km3 respectively. Outside China, the largest dam is Kaptai Dam in Bangladesh with a total storage capacity of 20 km3 (Table 7).
The main transboundary rivers in Southern and Eastern Asia are the Mekong river basin flowing to the South China Sea, the Ganges-Brahmaputra-Meghna river basin flowing to the Bay of Bengal, the Indus river basin flowing to the Arabian Sea and the Salween river basin flowing to the Andaman Sea. These four transboundary river basins cover almost one-fifth of the total area of Southern and Eastern Asia (Table 8 and Figure 9). A more detailed description of these four transboundary basins is given in Section III.
Water withdrawal by sector
Data on water withdrawal by sector refer to the gross quantity of water withdrawn annually for a given use. Table 32 presents the distribution of water withdrawal by country for the three large water-consuming sectors: agriculture (irrigation, livestock watering, aquaculture), municipalities (domestic/municipal) and industry (including water for cooling of thermoelectric plants). Although able to mobilize a significant portion of water, requirements for energy purposes (hydroelectricity), navigation, fishing, environment and leisure activities have a low rate of net water consumption. For this reason, they are not included in the calculation of the regional withdrawals but they do appear in the country profiles where information is available.
For most countries, data on water withdrawal could be obtained from national statistics although large uncertainties remain on computation methods. For five countries (Democratic People’s Republic of Korea, Lao People’s Democratic Republic, Malaysia, Mongolia and Nepal) data for water withdrawal could not be found in national reports and estimates were done based on modelled data for municipal and industrial water withdrawal using statistical methods and calculated based on irrigation areas, cropping patterns, consumptive water use and efficiency for agricultural withdrawal. It should be noted that these are countries where water resources are not yet a constraint on economic development.
Total annual water withdrawal for the Southern and Eastern Asia region is almost 1 981 km3, which is around 50 percent of world withdrawals (Table 9 and Table 39). It should be noted here that the total population of the region is more than half the world population. About 82 percent of inventoried withdrawals are by agriculture, which is higher than the value for global agricultural water withdrawal (70 percent). However, this figure varies by country. In 14 out of 22 countries in the region agricultural withdrawal accounts for more than 80 percent of the total water withdrawal, with more than 95 percent in Viet Nam and Nepal, while in Malaysia and Mongolia it represents less than 50 percent, and in the Maldives and Papua New Guinea 0 percent. The Mainland Southeast Asia and South Asia countries use on average 92 and 91 percent respectively of their withdrawal for agriculture while Maritime Southeast Asia countries use 79 percent and East Asia countries use only 65 percent.
Not surprisingly, considering the population, India and China with a water withdrawal of 761 km3 and 554 km3 respectively cover the highest withdrawals in the world, accounting for 19 percent and 14 percent of the total respectively, while in the Southern and Eastern Asia region they represent 38 and 28 percent respectively of total withdrawal. Pakistan and Indonesia represent 5 percent and 3 percent respectively of world total withdrawals and 6 and 9 percent of total withdrawals for Southern and Eastern Asia region. Viet Nam has the highest withdrawal in the Mainland Southeast Asia subregion at 4 percent of the total withdrawals in the region (Table 32). Water withdrawal per inhabitant is 560 m3/year, but this average conceals significant variations between countries. The figure ranges from 10 and 60 m3/inhabitant in the Maldives and Papua New Guinea respectively to 1 037 m3/inhabitant in Pakistan and 1 232 m3/inhabitant in Timor-Leste (Figure 10).
Figures for agricultural water withdrawal expressed in m3 per hectare of irrigated land show large discrepancies between countries, which cannot be explained solely by differences in climatic conditions. Rather, their difference is to be found in computation methods. Indeed, with a major regional emphasis on flooded rice irrigation, it is particularly difficult to assess agricultural water withdrawal. The gross average for the region is 8 960 m3/ha/year. Figures for China and India, which together represent 64 percent of the region’s agricultural water withdrawal, are: 5 700 and 10 400 m3/ha of irrigated land respectively. However, other countries show much higher values, as for Viet Nam, Republic of Korea, Sri Lanka, Timor-Leste and the Philippines where agricultural water withdrawal is between 15 000 and 35 000 m3/ha/year. More research is needed to obtain homogenous information on agricultural water withdrawal among countries.
Municipal water withdrawal is particularly important in the East Asia subregion with 75 km3 accounting for 13 percent of total withdrawals, while in Maritime Southeast Asia it represents 11 percent, in South Asia 7 percent and in Mainland Southeast Asia 4 percent. Municipal water withdrawal per inhabitant is 50 m3/year for the Southern and Eastern Asia region as a whole, with variations between countries from 5 m3/inhabitant in Nepal to 150 m3/inhabitant in Malaysia and 141 m3/inhabitant in the Republic of Korea. Industrial water withdrawal is particularly important in the East Asia subregion with 133 km3 accounting for 23 percent of total withdrawals, while in Maritime Southeast Asia it represents 10 percent, in Mainland Southeast Asia 4 percent and in South Asia 2 percent. Industrial water withdrawal in China is 129 km3, which is 71 percent of the region, followed by India with 17 km3 or 9 percent. Industrial water withdrawal per inhabitant is 51 m3/year for the Southern and Eastern Asia region on average. However, this figure also varies considerably at country level. In nine countries it amounts to less than 10 m3/inhabitant per year, especially for the Maldives and Nepal where industrial water withdrawal is 1 m3/inhabitant per year, whereas in Malaysia and China the figures are 183 and 97 m3/inhabitant per year respectively.
Water withdrawal by source
Data on water withdrawal by source refer to the gross quantity of water withdrawn annually from all the possible sources, which are divided into primary and secondary (wastewater and agricultural drainage water returned to the system) freshwater resources, direct use of treated wastewater and agricultural drainage water, and desalinated water produced. Table 10 presents the distribution of water withdrawal by subregion.
For most countries, the methods used for calculation or the measurements for obtaining the values of the withdrawal by source are not specified. For countries for which recent data were not available or were not reliable, estimations have been used that take into account total water withdrawal by sector, given that total water withdrawal by source and total water withdrawal by sector must be equal.
Total annual water withdrawal by source is 1 980.829 km3 for the Southern and Eastern Asia region, which is equal to half of the global water withdrawal (Table 33 and Table 39). Primary and secondary freshwater accounts for 1 853.758 km3 or 93.585 percent of total water withdrawal, direct use of treated wastewater and agricultural drainage water accounts for 127.035 km3 or 6.413 percent, and desalinated water accounts for 0.036 km3 or 0.002 percent. However, while only for India a figure is given for direct reuse of agricultural drainage water, this must the case in many other countries where rice is grown on terraces and irrigated with water flowing from one plot to another lower lying plot (cascades).
Considering the 13 countries out of 22 in the region, for which data on surface water and groundwater withdrawal is available, surface water withdrawal represents 75 percent of the freshwater withdrawal and groundwater 25 percent. Though, there are differences depending on the subregion. In Mainland and in Maritime Southeast Asia, surface water amounts to 92 and 90 percent of the total respectively, while in the East Asia countries surface water accounts for 82 percent and in the South Asia countries surface water accounts for 65 percent. In Bhutan, Brunei Darussalam, Viet Nam, Malaysia and the Philippines surface water withdrawal represents more than 95 percent of the total freshwater withdrawal, whereas in Mongolia and Bangladesh groundwater withdrawal accounts for 82 percent and 79 percent respectively.
From data reported, Maritime Southeast Asia seems the most advanced subregion regarding production of desalinated water accounting for 0.023 km3, which represents 0.01 percent of the total water withdrawal in the subregion. East Asia follows with 0.011 km3 or only 0.002 percent of the total withdrawal. In the Mainland Southeast Asia countries there is no information on desalinated water available, while in South Asia only 0.002 km3 are reported. Maldives is the only country in the region where desalinated water represents more than 1 percent of total withdrawals, accounting for 21 percent of the total.
The water indicator of the Millennium Development Goals
The Millennium Development Goal (MDG) water indicator, which is the total freshwater withdrawal as a percentage of total renewable freshwater resources, reflects the overall anthropogenic pressure on freshwater resources. In many areas, water use is unsustainable: withdrawal exceeds recharge rates and the water bodies are overexploited. The depletion of water resources can have a negative impact on aquatic ecosystems and, at the same time, undermine the basis for socio-economic development.
When relating the freshwater withdrawal to the renewable water resources in the Southern and Eastern Asia region, 18 out of 22 countries of the region stand out with values lower than 20 percent indicating that the water withdrawn is much lower than the quantity annually renewed on a long-term basis (Table 11 and Table 33). Pakistan has by far the highest water indicator, 74 percent, thoughIndia, Republic of Korea, Sri Lanka and China follow with 40, 37, 25 and 19 percent respectively (Figure 11). However, there can be huge within-country differences, especially in the many large countries in this region, and certain areas in a country are confronted with serious water scarcity issues.
Considering subregions the percentage of use of renewable water resources is lower in Mainland Southeast Asia and Maritime Southeast Asia, with total freshwater withdrawal amounting to only 5.4 percent of renewable water resources on average. In East Asia and South Asia water withdrawal represents 20 percent and 27 percent respectively of total renewable water resources.
Evaporation losses from artificial reservoirs
The evaporation from artificial lakes and reservoirs is considered a consumptive water use, since it would not occur if they had not been constructed to retain the water and thus create a surface water body from which water evaporates. This variable does not include evaporation from natural wetlands, natural lakes and rivers.
In theory this amount should be added to the water withdrawal data, but for the moment the information is still too uncertain and a more in-depth study is needed to confirm and complete the information for the whole region. However, a first effort to calculate the evaporation for the Southern and Eastern region, gives a value of 50 km3/year, representing about 2.5 percent of the total water withdrawal (Table 12). By far the largest values are for India, with 16.95 km3/year, and China, with 15.46 km3/year.
IRRIGATION AND WATER MANAGEMENT
Methods used by countries to estimate their irrigation potential vary, with significant influence on the results. In computing water available for irrigation, some countries only consider renewable water resources, while others, especially arid countries, include the availability of fossil or non-conventional sources of water. For this reason, comparison between countries should be made with caution. In the case of transboundary rivers, calculation by individual countries of their irrigation potential in the same river basin may lead to double counting of part of the shared water resources. It is therefore not possible to systematically add up country figures to obtain regional estimates of irrigation potential.
The largest irrigation potential is reported by India, 139.5 million ha, followed by China with 70 million ha and Pakistan with 21 million ha (Table 35). While the irrigation potential in Cambodia has never been estimated in terms of physical area, which could be irrigated considering water and land resources, it could be at least 1 million ha. For those countries without data – Bhutan, Brunei Darussalam, Democratic People’s Republic of Korea and Timor-Leste – the irrigation potential is estimated as the total area equipped for irrigation, in order to be able to calculate a regional average. The irrigation potential of Southern and Eastern Asia is estimated at, at least, 292.5 million ha, of which 72 percent corresponds to India (48 percent) and China (24 percent). The countries in South Asia (including India) account for 58 percent of the total irrigation potential of Southern and Eastern Asia, followed by East Asia (including China) with 25 percent and Mainland Southeast Asia with 12 percent, whereas Maritime Southeast Asia represent barely 5 percent. It is currently estimated that the total water managed area represents 64 percent of the irrigation potential in the region, ranging from 89 percent in East Asia, and 84 percent in Maritime Southeast Asia to 56 percent in South Asia and 43 percent in Mainland Southeast Asia.
Typology of irrigation and water management
In most countries of the region irrigation has a long history that is closely linked to the history of rice cultivation. Asia, in general, and the region covered by this survey in particular, represent the bulk of irrigation in the world. The region itself accounts for about 60 percent of the world’s irrigation (Table 39). High population density combined with the tradition of irrigated rice cultivation in all the tropical parts of the region are the main factors explaining the importance of irrigation in Asia.
In many countries of the region, irrigation is viewed as an important input to the agricultural production systems. While irrigation development dates back several centuries, the twentieth century, and particularly its second half, saw a rapid increase in what could be called modern irrigation development and a majority of the countries achieved self-sufficiency in cereal crops, mostly rice.
The total area where water other than direct rainfall is used for agricultural production has been named ‘area under water management’. The term ‘irrigation’ refers to areas equipped to supply water to crops. Table 34 and Table 35 present the distribution by country of these areas under water management, making a distinction between areas under irrigation, which is the sum of full control irrigation areas, spate irrigation areas, and equipped lowlands (wetlands, inland valley bottoms and flood recession areas) and areas under other forms of water management, which are non-equipped lowlands (wetlands, inland valley bottoms and flood recession cropping areas). The distinction between irrigation and water management is sometimes difficult. In particular, the demarcation between equipped and non-equipped lowland areas is often vague.
The assessment of land under irrigation in the countries of the region is made particularly difficult by the different approaches used in the countries to compute irrigation. For some countries (for example Bangladesh, Bhutan) paddy fields, cultivated mainly during the wet season, are not considered as irrigated land. For other countries where paddy rice cultivation is practiced, all paddy fields are considered irrigated land. In most cases, schemes are designed primarily to secure rice cultivation in the main cropping season, although the need for intensification has progressively led some countries to design new irrigated schemes for year-round irrigation, for example Thailand, while Viet Nam has three rice crops a year.
The total area equipped for irrigation covers more than 181 million ha in the Southern and Eastern Asia region, but the geographical distribution is very uneven, both from subregion to subregion and from country to country (Table 13, Table 34, Table 35, Figure 12 and Figure 13). About 83 percent of the area equipped for irrigation is concentrated in India (37 percent), China (35 percent) and Pakistan (11 percent). The Maritime Southeast Asia subregion countries account for 5 percent of the area equipped for irrigation, which is a low value taking into account that their total area is 15 percent of the region. Within this sub-region, Indonesia has the largest area equipped for irrigation, accounting for 4 percent of the total area of the Southern and Eastern Asia region, followed by the Philippines, which represents 1 percent. Within the Mainland Southeast Asia subregion, Thailand has the largest area equipped for irrigation, accounting for 4 percent of the total area of the region, followed by Viet Nam, which represents 3 percent (Table 34).
In this survey, figures on spate irrigation have only been provided for Mongolia and Pakistan, amounting to 27 000 ha and 720 000 ha respectively (Table 14 and Table 34). It should be noted that during the previous survey the figure reported for spate irrigation in Pakistan was double the figure reported this time. It is not clear whether the previous figure was wrong or whether, maybe, a large part of the area that was previously reported under spate irrigation, has in the mean time become full control irrigation. Equipped lowlands are frequent in countries with more renewable freshwater resources, such as Malaysia and Myanmar, amounting to 21 970 ha and 27 000 ha respectively.
Full control irrigation, which covers 180 million ha, is by far the most widespread form of irrigation in the Southern and Eastern Asia region. It accounts for 99.6 percent of the area equipped for irrigation.
Irrigation is practiced on 41 percent of the total cultivated area of the region compared to 18 percent globally (Table 14, Table 39 and Figure 14). This is the highest level compared to the other major regions of the world. In the East Asia and South Asia subregions it is 48 percent and 46 percent of the cultivated area under irrigation respectively, while in Mainland Southeast Asia and Maritime Southeast Asia the area equipped for irrigation accounts only for 31 and 16 percent (Table 14). At county level, Pakistan has the highest level, with 94 percent of cultivated land under irrigation, followed by Bangladesh with 58 percent and Democratic People’s Republic of Korea with 56 percent. Nepal, Republic of Korea, China and Viet Nam have more than 45 percent of cultivated land under irrigation. On the other hand, Malaysia, Cambodia and Mongolia have less than 10 percent of the cultivated area under irrigation (Table 34).
While most wet season rice irrigation is fully gravity irrigation (cascades from plot-to-plot), dry season cropping may require pumping in places. This is the case in Lao People’s Democratic Republic where, owing to the pumping costs, dry season rice cropping has not proved economic unless a very bad harvest has been recorded in the previous wet season. In the tropical zone, wet season irrigation is almost only paddy rice. It is usually considered as supplementary irrigation to an already abundant precipitation. During the dry season, a much larger diversity of crops are grown on irrigated fields. In Cambodia, Indonesia, Malaysia and Mongolia, a kind of flood control irrigation is practiced with flood water being used to inundate paddy fields that are then cultivated with rice.
Full control irrigation techniques
Table 15 presents the subregional distribution of irrigation techniques used on areas under full control irrigation. Data are available for all countries, except Nepal and Timor-Leste. For the purpose of the analysis in Table 15, it was assumed that 100 percent of the area in these two countries used the surface irrigation technique. For India and the Republic of Korea, which have earlier data by technique than for the total full control irrigation area, the percentages for each of the techniques were retained and applied to the areas currently under full control. Therefore, these values are in order of magnitude only and are not an exact reflection of the real situation. However, it seemed worth attempting to complete the data based on the field knowledge of the AQUASTAT team in order to form a more precise picture of the irrigation techniques used in the Southern and Eastern Asia region. Table 36, however, provides the exact data available by country and the year to which they refer, which means that the sum of the different techniques is not equal to the total area equipped for full control irrigation. As shown in Table 15, surface irrigation, accounting for 96.8 percent of the irrigation techniques, greatly exceeds pressurized irrigation techniques, which are sprinkler irrigation (2.4 percent) and localized irrigation (0.8 percent). Surface irrigation includes all paddy rice cultivation and most of the other crops. In most countries, sprinkler or localized irrigation systems are reported to exist only on very small, experimental plots.
In Mainland and Maritime Southeast Asia pressurized irrigation represents less than 0.01 percent and 0.2 percent of the full control irrigation area respectively. In South Asia sprinkler irrigation accounts for 1.6 percent and localized irrigation for 0.6 percent while in East Asia sprinkler irrigation represents 4.4 percent and localized irrigation 1.2 percent. Mongolia is the only country where sprinkler irrigation represents a significant part (75.7 percent) of the area under irrigation as large schemes were systematically equipped with sprinkler irrigation in the 1980s. Besides Mongolia, there is information on pressurized irrigation techniques only for five other countries. In China, sprinkler irrigation and localized irrigation represents 4.5 percent and 1.2 percent respectively of total full control irrigation, while in India they account for 2.3 percent and 0.9 percent respectively. In the Philippines, localized irrigation represents 0.6 percent and sprinkler irrigation 0.2 percent of the irrigation techniques. In Malaysia, 0.03 percent corresponded to localized irrigation in 1994. In Viet Nam, sprinkler irrigation accounts for only 0.02 percent of the area under full control irrigation (Table 36).
Origin of water in full control irrigation
Table 16 presents available data concerning the origin of irrigation water in the areas under full control irrigation: Primary and secondary surface water, groundwater, and mix of surface water and groundwater. While certainly several countries, especially in the case of rice growing, will directly use agricultural drainage water by irrigating from one plot to the next lower lying plot (cascade), no information on this was available. For the purpose of the analysis in Table 16, it was assumed that for those countries with earlier data on origin of water compared to full control irrigation data, which are Cambodia, Democratic People’s Republic of Korea, India, Republic of Korea and Sri Lanka, the percentages for each of the sources were retained and applied to the areas currently under full control. Therefore, these values are in order of magnitude only and are not an exact reflection of the real situation. However, it seemed worth attempting to complete the data based on the field knowledge of the AQUASTAT team in order to form a more precise picture of the sources of water used for irrigation in the Southern and Eastern Asia region. In Table 37, however, the exact information as available is given for all countries, which means that the sum of the different sources is not equal to the total area equipped for full control irrigation.
Regarding ‘other sources of water’, Pakistan accounts for the highest percentage with 41 percent of mixed surface water and groundwater (Table 37). In the Philippines, 16 percent of the area for irrigation uses a mix of surface water and groundwater, while in Nepal, this area accounts for 1 percent. No information is available in the other countries on other sources of water.
Surface water is the major source of irrigation water in the Southern and Eastern Asia region as a whole (56 percent on average), since countries such as China, Indonesia, Thailand and Viet Nam, which have large areas under irrigation, irrigate mainly with surface water (69, 99, 91 and 99 percent respectively). In Bangladesh, India and Mongolia groundwater represents 79, 64 and 63 percent respectively. Looking at the subregions, in Mainland and Maritime Southeast Asia, surface water accounts on average for 95 percent of the area equipped for irrigation. In the East Asia subregion, surface water accounts for 70 percent of the area equipped for irrigation and groundwater for 30 percent, while in South Asia groundwater accounts for 55 percent, surface water for 36 percent, mixed surface water and groundwater for 9 percent and non conventional sources of water for 0.3 percent (Table 16).
Information on power irrigated area is available only for 12 countries out of 22 of the region. The percentage of power irrigated area over equipped area for irrigation is important in Bangladesh, India, China and Viet Nam with 97, 83, 57 and 47 percent respectively. In Sri Lanka, Republic of Korea, Lao People’s Democratic Republic and Philippines it accounts for 30, 20, 15 and 14 percent respectively, while in Malaysia, Thailand, Myanmar and Bhutan the corresponding figures are only 10, 7, 4 and 3 percent respectively.
The definition of large schemes varies from one country to another. While certain countries, such as Bhutan, Cambodia and Sri Lanka, consider a large scheme to be 100, 400 and 500 ha respectively, other countries, such as India, China and Pakistan classify a large scheme as a minimum of 10 000, 20 000 and 25 000 ha respectively. Viet Nam even considers large schemes to be those over 50 000 ha.
A scheme is often described by its type of management, rather than by its size. In China, the very large, large and medium irrigation schemes are generally administrated by special governmental organizations. The small ones are usually farmer managed. In India, sources for minor irrigation projects generally have both surface water and groundwater, while major and medium projects exploit surface water resources. In Bangladesh, large-scale schemes are represented by major irrigation. In Malaysia there are three types of irrigation schemes: granary schemes, mini-granary schemes and non-granary schemes. The non-granary schemes are scattered throughout the country and their size varies between 50 and 200 ha.
Table 17 shows the scheme sizes in several countries and the criteria used. If no recent information on scheme sizes is available, the information from the previous survey is used, as for Brunei Darussalam, Cambodia, India, Malaysia and Republic of Korea.
CULTIVATION IN FULL CONTROL SCHEMES
Level of use of areas equipped for full control irrigation
It is difficult to calculate the areas actually irrigated in the Southern and Eastern Asia region because information is missing for many countries in both AQUASTAT surveys. Where a country did not have new data, the percentages of the previous survey are used. Given that data about actually irrigated areas are available for only 13 out of the 22 countries, Table 18 only shows these countries.
In Bangladesh, Bhutan, Myanmar, Pakistan and Viet Nam the total area equipped for full control irrigation is said to be actually irrigated. Cambodia and India have a rate exceeding 90 percent and Thailand, Timor-Leste, Sri Lanka, China and Lao People’s Democratic Republic have a rate ranging from 79 to 87 percent. Mongolia has a lower use rate accounting for 61 percent. In numerous cases, low rates are explained by deterioration of the infrastructure because of a lack of maintenance (caused by insufficient experience or the use of unadapted techniques) or political and economic reasons. Other causes are: inadequate management of technical means of production under irrigation, soil impoverishment, local instability and insecurity, and the reduction of public funds allocated to irrigation.
Cropping intensity, another indicator of the use of equipped areas, is calculated based on the area actually irrigated in full control irrigation for the eleven countries for which actually irrigated area and harvested irrigated crops area is available. For another seven countries, actually irrigated area is estimated to be equal to the area equipped for full control irrigation. Thus cropping intensity is probably underestimated because the area actually irrigated might be smaller than equipped area in several of these seven countries. In two countries (the Maldives and Papua New Guinea), no irrigation is said to be practiced, while for the remaining two countries (Mongolia and Timor-Leste) no information on harvested irrigated crop area was available. The calculation only refers to irrigated crops. This means that in a country with one or two wet seasons only the crops grown under irrigation are considered. The crops grown on the full control equipped area during the wet season without irrigation (but using the residual soil humidity) are not included in the irrigated crop area when calculating cropping intensity.
Cropping intensity by subregion ranges from 121 percent in South Asia to 159 percent in Mainland Southeast Asia, 169 percent in East Asia and 184 in Maritime Southeast Asia (Table 19). National cropping intensity ranges from 103 percent in Bhutan to 199 percent in Indonesia (Table 38). Cropping intensity for the Democratic People’s Republic of Korea and Malaysia has not been included in Table 38 because data on harvested irrigated area is from 2006 while actually irrigated area refers to 1995 and 1994 respectively, though it is included in Table 19.
Table 20 shows the cropping intensity for those eleven countries where the area actually irrigated is available and, therefore, it is easier to evaluate the real situation. As shown, figures range from 103 percent in Bhutan, meaning that approximately one crop per year is irrigated, to 190 percent in Viet Nam, meaning that almost two crops per year are irrigated on the same area.
The calculation of cropping intensity is straightforward for dry countries because irrigation is indispensable for the growing of crops in all seasons. However, the calculation is more problematic for countries with one or more wet seasons. In this case, for two crop cycles a year, only one is irrigated (during the dry season), the second uses soil moisture provided by precipitation. Therefore, the cropping intensity (irrigated crops only) is 100 percent on the area considered, while the harvested area is double.
Irrigated crops in full control schemes
Table 38 shows the national distribution of harvested irrigated crops for those countries that have provided such information. In many countries’ statistics no distinction is made between crops that are irrigated and rainfed crops, though in this survey efforts have been made to provide the most accurate data on irrigated crops. Table 21 provides data of the distribution of irrigated crops by subregion.
Cereals represent 70 percent of all harvested irrigated crop areas in the region. Rice alone represents about 39 percent of all harvested irrigated crop areas in the region. However, its regional distribution shows major trends: in the Mainland and Maritime Southeast Asia subregions, rice represents more than 80 percent of harvested irrigated crops, while in the East Asia and South Asia subregions rice represent 34 and 29 percent respectively. Wheat is the second most widespread harvested irrigated crop in the region, accounting for 23 percent on average, mainly cultivated in the South and East Asia subregions where wheat represents 30 and 23 percent of the total harvested irrigated cropped area respectively. Maize represents 6 percent, with special importance in East Asia (10 percent) and Maritime Southeast Asia (8 percent). The group of vegetables, roots and tubers accounts for 5 percent of the total irrigated cropped area of the region, of which 8 percent are potatoes and sweet potatoes. This group of vegetables, roots and tubers represents 10 percent of the total area in the East Asia subregion. In the South Asia subregion, cotton, sugarcane and pulses account for 5, 5 and 4 percent respectively of the harvested irrigated crops area. Other important crops in the region are soybeans, groundnuts, citrus and tobacco. Permanents crops account for approximately 8 percent.
As shown in Table 38, rice is the main crop in most countries in the region, in many countries representing more than 90 percent of the total harvested irrigated area. By contrast, Pakistan, India, China, Democratic People’s Republic of Korea and Nepal have a much more balanced distribution of irrigated crops with rice representing only about one-third or less of the total harvested irrigated crop area. This reflects the cold or arid context of large parts of these countries. In Pakistan, rice represents only 12 percent of the total harvested irrigated crop area, whereas wheat represents 34 percent and fodder 12 percent.
In India, the percentage of harvested area under irrigated wheat is slightly higher than that under irrigated rice (31 percent against 29 percent), the rest being shared between a large variety of crops. In China, rice is the single most important harvested irrigated crop accounting for 34 percent of the total harvested irrigated crop area, followed by wheat with 24 percent, maize with 10 percent and vegetables (including roots and tubers) with 10 percent. However, as reported in the previous survey, done in 1999, in India only 47 percent of the total harvested area for paddy rice was irrigated, while more that 92 percent of the harvested paddy rice in China was irrigated. In Nepal, the percentage of harvested area under irrigated rice is slightly higher than that under irrigated wheat (37 percent against 34 percent).
TRENDS IN THE LAST TEN YEARS
Ten years ago the population of the Southern and Eastern Asia region was 3 225 million, or 53 percent of the world’s population (1999). Currently it is 3 605 million, still 53 percent of the world’s population (2009). Population density has risen from 154 to 173 inhabitants/km2. The annual rate of population growth over the last ten years is 1.1 percent, a decrease from the 1.6 percent/year for 1989–1999. While ten years ago about 67 percent of the population in the Southern and Eastern Asia region lived in a rural environment, currently it is 61 percent (Table 2 and Table 30). This indicates that there is, even though slow, migration towards cities.
Water withdrawal by sector
On a sectoral basis, the proportions of water withdrawal have changed only slightly: agricultural water withdrawal has increased from 81 percent to 82 percent and municipal withdrawal from 7 percent to 9 percent while industrial withdrawal has decreased from 12 percent to 9 percent. However, total water withdrawal has grown by 4 percent over the last ten years (Table 22).
Between the two survey dates, annual withdrawal per inhabitant has decreased (by 25 m3). This is because of an increase in total population in the region and a decrease in total water withdrawal in the East Asia and Mainland Southeast Asia subregions from 658 km3 to 589 km3 and from 199 km3 to 179 km3 respectively. Maritime Southeast Asia is the only subregion in which annual water withdrawal per inhabitant has increased, from 385 m3 to 634 m3.
Looking at the municipal sector, water withdrawal per capita has increased from 40 m3/year, or 110 litres/day, to 50 m3/year, or 137 litres/day. There is quite some variation between the subregions and between countries. In the East Asia subregion it has increased from 37 to 54 m3/year, in South Asia from 43 to 44 m3/ha, while in the maritime Southeast Asia subregion there has been a large increase from 41 to 71 m3/year. However, in the Mainland Southeast Asia subregion it has decreased from 40 to 34 m3/year.
In agriculture, the annual water withdrawal per hectare of area equipped for irrigation seems to have decreased from 10 700 m3 to 9 000 m3. The reason for this is not fully clear. It could be a result of computation methods, data quality, changed cropping pattern or an improvement in irrigation techniques. In the East Asia subregion it has decreased from 8 000 m3 to 5 800 m3, in the South Asia subregion from 11 500 m3 to 9 800 m3 and in the Mainland Southeast Asia sub-region from 17 100 m3 to 12 000 m3. However, in the Maritime Southeast Asia subregion it has increased from 16 100 m3 to 18 400 m3. These data should be used with caution since, as mentioned above, the reason for these changes are not fully clear. It may be that different methods have been used to calculate agricultural withdrawal and irrigation areas.
Water withdrawal by source
For the Southern and Eastern Asia region as a whole, annual freshwater withdrawal has increased from 1 895.408 km3 to 1 980.793 km3, which represents an annual rate of increase of 0.4 percent (Table 23). Desalinated water has increased from 0.024 km3 to 0.036 km3, equal to an annual increase of 4.1 percent. Thus, freshwater remains by far the most important source, accounting for 99.998 percent of the total while in the previous survey it accounted for 99.999 percent of the total.
The countries with data on desalinated water, reported figures that are practically the same as for the previous survey. There is no new information for India, Indonesia and Malaysia so the same value is presented as for 1999. Maldives has increased from 0.37 million m3 to 1.225 million m3. China and the Republic of Korea report using desalinated water, 11 million m3 and 0.16 million m3 respectively, while in 1999 no data were available. Figures on direct use of treated wastewater and agricultural drainage water are available for only three countries. China reported 13 390 million m3 of direct use of treated wastewater in the previous survey, though no new information was given for the present survey and Viet Nam reports 175 million m3 in the present survey. Direct use of agricultural drainage water is reported by India accounting for 113.47 km3 in 2007. This does not mean that it was equal to zero in the previous survey, just that no data were available at that time. In Table 23 the data on direct use are included in the freshwater data.
Areas under irrigation
Table 24 presents the trends in the area under irrigation during the last ten years. It should be taken into account that the information for some of the countries is for earlier years as new data were not provided (Table 34).
For the Southern and Eastern Asia region, the increase in the equipped area is 27 percent, which is equal to an annual rate of 1.88 percent using a weighted year index. This is calculated by allocating a weighting coefficient to the year for each country that is proportional to its area equipped for irrigation, therefore giving more importance to countries with the largest areas under irrigation.
The area under full control irrigation has an annual rate of increase of 1.93 percent, which is a little higher than the annual rate for total irrigation. This is explained by the fact that the area of spate irrigation has not increased as much as the area of full control irrigation (in fact, as mentioned earlier the figure for spate irrigation in Pakistan, reported during the present survey, is half of the area reported ten years ago) and because equipped lowlands area have not increased since 1999.
The Maritime Southeast Asia subregion has a relatively high annual rate of increase of 3.7 percent (Table 24). However, this could also be explained by the reclassification of areas previously indicated as non-equipped water managed areas (see glossary for definitions and Table 13), which have been counted as equipped areas this time because of better knowledge of the field situation. Indonesia has the largest annual increase in equipped areas in this subregion, which accounts for 4.3 percent. Malaysia and the Philippines have shown annual rates of increase of 1.5 percent (Table 34).
The Mainland Southeast Asia subregion has an annual rate of increase of 2.9 percent. The annual rate for Cambodia is 4.5 percent, the largest increase in equipped areas in the Southern and Eastern Asia region. Other countries in the Mainland Southeast Asia subregion, such as Viet Nam and Myanmar, have shown annual rates of increase of 3.9 and 3.5 percent respectively, while the annual increase in Thailand is 2.1 percent and in Lao People’s Democratic Republic 1.0 percent.
In the South and East Asia subregions the annual rate of increase is 1.7 percent. Nepal and Bangladesh have an annual rate of increase of 2.9 percent and 2.1 percent respectively. The Republic of Korea has shown a drop in areas equipped for irrigation, at an annual rate of -0.9 percent.
Table 25 presents the trends in irrigation techniques. For Nepal and Timor-Leste there is no information on irrigation techniques, thus, to facilitate the comparison between 1999 and 2009, we have estimated all the full control area under surface irrigation in both years.
The area under surface irrigation, the most important technique, has increased by 34.5 million ha (25 percent). However, in all subregions except Mainland Southeast Asia, the relative importance of surface irrigation has decreased. Sprinkler irrigation has increased by 3 million ha, which represents a growth rate of 219 percent for this technique. While its relative importance is lower in the Mainland and Maritime Southeast Asia subregions, it has grown especially in East Asia followed by South Asia. Localized irrigation, which is the technique that requires less water, has increased in area by 1.3 million ha, representing a growth rate of 1 827 percent since the previous survey ten years ago. It is developing most in the East and South Asia subregions, where the percentage, compared with the other techniques, has increased from 0 to 1.2 percent and from 0.1 to 0.6 percent respectively. In Maritime Southeast Asia localized irrigation increases in importance only from 0 to 0.1 percent of the total area, while in Mainland Southeast Asia no country has reported the use of this irrigation technique. While growing in importance, the Southern and Eastern Asia region has not yet adopted a large area of sprinkler and localized irrigation. While this maybe explained by its humid weather, or the types of crops (rice), the reasons will have to be studied more in-depth.
Origin of water for irrigation
Table 26 presents the trends in the distribution of the origin of water used in full control irrigation. For China, Timor-Leste and Viet Nam there is no data on the origin of water for irrigation in the previous survey. To facilitate the comparison between 1999 and 2009, we have estimated the same proportion of surface water and groundwater as in the present survey, even though this might not be fully correct.
As shown in Table 26, data on the origin of water used from a mix of surface water and groundwater have been considered in the present survey, while in the previous one only surface water or groundwater were considered. For these reasons the following statistics must be considered with caution. The area irrigated by groundwater has increased from 53 million ha to 71 million ha, which represents a change from 37 percent to 39 percent of the total full control equipped area. In the Mainland Southeast Asia subregion the groundwater proportion has increased from 1 percent to 5 percent, while in the South Asia subregion it has increased from 52 percent to 55 percent. In East Asia, the same proportion of area irrigated by groundwater and surface water is estimated in the previous and present survey. For the whole region, the area irrigated by surface water has increased from 89 million ha to 101 million ha, but its proportion over the entire area under full control irrigation has decreased from 63 to 60 percent. However, another 5 percent of the area has been irrigated by a mix of surface water and groundwater. The area irrigated by groundwater has increased from 53 million ha to 71 million ha, meaning that its proportion in the whole area under full control irrigation has increased from 37 to 39 percent.
There is no irrigation in Maldives and Papua New Guinea and there is no information on harvested irrigated crop area for Mongolia and Timor-Leste, thus they are not included in the totals. Furthermore, in the previous survey there were no data for irrigated crops in Indonesia. To facilitate the comparison between 1999 and 2009, we have estimated the harvested irrigated area by crop proportionally to the increase in full control irrigation area. For these reasons the following statistics must be considered with caution.
The main change in the last ten years has been an increase in rice areas from 68 million ha to 92 million ha and their proportion over the whole area under full control irrigation, from 37 percent to 39 percent. Wheat-growing harvested irrigated areas have increased from 49 million ha to 54 million ha, but their proportion to the whole area under full control irrigation has decreased from 27 to 23 percent. In the previous survey of 1999, however, 4 percent of the total harvested irrigated crop area was under ‘other cereals’ that could include rice or wheat, while in the present survey only 1 percent is under ‘other cereals’. Irrigated cereals as a percentage of total irrigated crops have decreased from 76 percent in 1999 to 69 percent in 2009. The area under vegetables including roots, tubers, potatoes, sweet potatoes and pulses has increased from 7 million ha to 17 million ha and their proportion over the entire area under full control irrigation has increased from 4 percent to 7 percent. The area under permanent crops has also increased from 5 to 8 percent, indicating that a higher percentage of irrigated area is dedicated to these crops. The proportion of other crops has not varied significantly over the whole area under full control irrigation.
Use rate of areas equipped for irrigation
Amongst the seven countries for which information is available – Bhutan, Cambodia, China, Lao People’s Democratic Republic, Myanmar, Thailand and Viet Nam – there has been an improvement in the use rate of equipped areas over the last ten years, in three countries it has decreased, and in three it has remained the same. Areas actually irrigated in Viet Nam, where there has been a large increase in equipped areas, have increased from 70 percent of equipped areas in 1994 to 100 percent in 2005. In China, the area actually irrigated has declined from 88 percent in 1996 to 86 percent in 2006, while equipped areas have notably increased. In Lao People’s Democratic Republic, where there has been a large increase in equipped areas, the area actually irrigated has decreased from 89 percent in 1995 to 87 percent in 2005. In Thailand the use rate has fallen from 91 percent to 79 percent between 1988 and 2007, for a large increase in equipped area. In Bhutan, Cambodia and Myanmar the area actually irrigated represented 100, 90 and 100 percent of the equipped areas respectively in both the previous and present surveys.
LEGISLATIVE AND INSTITUTIONAL FRAMEWORK OF WATER MANAGEMENT
In seven out of the 22 countries of the Southern and Eastern Asia region, for which information is given, water management is based on a water code or on a specific water law or act. A specific Water Law has been enacted in Indonesia (2004), Lao People’s Democratic Republic (1996), Mongolia (1995) and Viet Nam (1998). China and the Philippines have a Water Code, signed in 1988 and 1976 respectively. In Papua New Guinea, a Water Resources Act was signed in 1982, which is the statutory instrument under which the allocation and management of water resources proceed. In the other countries certain aspects of water management are regulated, but these specific arrangements are not grouped in a water code.
In Bangladesh, thus far no policy or act has been formulated related to irrigation or water management, however, in recent years policies such as the National Agriculture Policy, National Water Policy and the National Water Management Plan addressed, to some extent, the minor irrigation and water management issues. Bhutan has a Water Policy signed in 2003. In Cambodia, laws and policies related to water resources management are many and varied, including the Natural Water Resource Policy (2004) and the Law on Water Resources Management (2007). Agricultural policies of the Democratic People’s Republic of Korea are directed towards solving the problem of food shortages through the ‘four improvements’ in agricultural technology: irrigation, farm mechanization, rural electrification, and agricultural chemicals. India adopted a National Water Policy in 1987, which was revised in 2002. In Malaysia, although either directly or indirectly much legislation touches on water resources, most of the existing laws are considered outdated. The Water Act of 1920 is inadequate for dealing with the current complex issues related to water abstraction, pollution and river basin management. In the Maldives, different water management plans have been presented in the last decades.
In Myanmar, even though there is no single law covering all aspects of water resources, the laws deal with the subject in one way or another and many issues still need to be developed. In Nepal, an Irrigation Policy and a National Water Plan were signed in 2003 and 2005 respectively. In Pakistan, the Draft National Water Policy has been in the process of approval since 2005. The Pakistan Water Strategy was prepared during 2001, which is the basic document for the country’s water development and management. In Sri Lanka, there are over 50 acts of parliament concerning the water sector and laws are administered by numerous agencies with a wide range of responsibilities, and there are overlaps, gaps and conflicting jurisdictions. In Thailand, a draft Water Law has been in the process of approval since 2007. In Timor-Leste comprehensive and sophisticated policies are not currently warranted. No information on water legislation is available for Brunei Darussalam and the Republic of Korea.
For many Southern and Eastern Asia countries, the national institutions responsible for the management and planning of irrigation development are departments or divisions within the Ministry of Agriculture. In Bangladesh, minor irrigation schemes are under the jurisdiction of the Ministry of Agriculture and small-scale surface irrigation under the Ministry of Local Government, Rural Development and Cooperatives, while large-scale irrigation schemes are under the Ministry of Water Resources. In Bhutan, irrigation management depends on the Irrigation Agency, in Brunei Darussalam on the Department of Agriculture of the Ministry of Industry and Primary Resources and in the Philippines on the Department of Agriculture of the National Irrigation Administration. In Nepal there is a Ministry of Irrigation and in Thailand, irrigation is managed by the Royal Irrigation Department for public schemes, or by the Department of Water Resources. Some countries, as reported by Bangladesh, Bhutan, China, India, Philippines and Sri Lanka, have different institutions responsible for irrigation at the national, regional and local level.
Overall, the responsibility for water resources management, planning and development is shared by various government agencies and ministries (water resources, environment, natural resources, construction, transport or industry), in some cases there is little coordination between them. In some countries water resources management and development falls mainly under one institution, such as the Ministry of Water Resources in Bangladesh, the Ministry of Water Resources in China, the Water Resources Coordination Committee in Lao People’s Democratic Republic, the Ministry of Irrigation in Nepal and the Ministry of Natural Resources and Environment in Viet Nam.
In the Philippines, the National Water Resources Board is the overall government agency that is responsible for all water resources in the Philippines. In India, the federal states are primarily responsible for the planning, implementation, funding and management of water resources development, while the Ministry of Water Resources is responsible for laying down policy guidelines and programmes for the development and regulation of the country’s water resources. In Indonesia, the Department of Public Works is responsible for surface water resources, while the Department of Mining and Energy is authorized to manage groundwater resources. In Myanmar, the Ministry of Agriculture and Irrigation is the main ministry involved in water resources. Municipal water supply, wastewater treatment and water quality depend in some countries on another ministry again (such as health, environment, public works, housing and construction or rural development).
The development of hydropower depends on different ministries, departments and enterprises, such as the Department of Power in Bhutan, the Electric Power Enterprise within the Ministry of Electric Power in Myanmar, the Ministry of Water and Power in Pakistan, the National Power Corporation in the Philippines, the Ceylon Electricity Board in Sri Lanka and the Ministry of Industry in Viet Nam.
The management of the irrigation systems is generally performed jointly by the State, as regards the primary infrastructure or public systems, and by user associations or independent users for the secondary and tertiary infrastructure or private systems. China, Cambodia, India, Lao People’s Democratic Republic, Myanmar, Pakistan, Philippines, Republic of Korea, Sri Lanka, Thailand and Viet Nam have reported the importance of water user associations in the management of water and irrigation.
In most of the countries surface water and groundwater resources are state property. Water tarification is used in most countries of the region, although in different ways. China requires water charges to be collected according to the cost of water delivery. In India there is no uniform set of principles in fixing the water rates. They vary from stateto state, project to project and crop to crop, and are abysmally low and insufficient funds are generated for proper maintenance of irrigation systems, leading to poor quality of service. From the end of the 1960s, Indonesia made large investments into land and water resources development to achieve food self-sufficiency. Since the beginning of the 1990s, however, as Indonesia gained confidence in securing its national food supply, government investments in land and water resources gradually have been decreasing.
In the Lao People’s Democratic Republic electricity and operating costs are paid directly by farmers who are also responsible for all maintenance matters concerning secondary and tertiary canals. Until 1994, the Irrigation Department was responsible for the operation and maintenance of weirs, dams, pumps and primary canals, after which it was supposed to be handed over to water users associations. In many cases, however, operation and maintenance are still carried out by the Irrigation Department or its provincial services.
In Malaysia, it was estimated in 1999 that fees collected from farmers cover only 10-12 percent of the actual operational cost. In the Maldives, the domestic tariff is stepped to provide a minimum quantity of water per day at an affordable rate. Wastewater charges are also included in the water charge. The application of charges has made the public aware and willing to conserve and use water judiciously. Mongolia’s Law on Water covers pricing policies intended to ensure cost recovery and the equitable allocation of water resources. In 2008, however, only about 65 percent of water costs were recovered through pricing, partly because of the country’s present economic conditions. In Myanmar, the water tariff covering the Irrigation Department’s gravity irrigation systems is very low and does not recover the cost of maintenance work. However, the water tariff in the river pumping systems of the Water Resources Utilization Department is higher. The annual budget for the maintenance and repair of the facilities is mostly paid by the government.
In Nepal there is a traditional belief that water is a God-given free commodity and only the water supplied to urban areas for domestic use is charged on a volumetric basis. Irrigation water is levied as a service charge. In Pakistan, the difficulties faced in cost recovery (44 percent) have resulted in very poor operation and maintenance. Farmers’ organizations are responsible for collecting the water fees. In Sri Lanka, the government instituted an irrigation fee for the first time in 1984. In Viet Nam, irrigation fees were first established in 1984 in some provinces. Funds are based on water users (farmers), payment (irrigation fees) and the government budget subsidy.
In most countries of the region there has been financial assistance (grants and loans) from international donors and foreign governments, such as the World Bank (WB), International Bank for Reconstruction and Development (IBRD), Japan International Cooperation Agency (JICA), Japan Bank for International Cooperation (JBIC), and Asian Development Bank (ADB), for major construction projects directed at the agricultural and energy sectors.
ENVIRONMENT AND HEALTH
In the Southern and Eastern Asia region, surface water and groundwater quality is commonly affected by agricultural, industrial and municipal wastewater. This is now being compounded by the mobilization of naturally occurring arsenic in sediments of the Ganges-Brahmaputra system as deeper groundwater circulation is exploited for agriculture and water supply.
Although total water withdrawal, as compared to water resources, remains limited in many countries in the region, the large amounts of water diverted, mostly for agriculture, have an environmental impact that may represent locally significant proportions. In several countries, or regions within countries, competition for water is becoming increasingly important, with direct implications for agriculture.
Upstream river water quality is generally good, but downstream sections of major rivers reveal low water quality. Agriculture, the development of industry and increasing population density is causing river pollution and health risks for people living close to the rivers. Much of the pollution results from inadequate treatment of municipal and industrial wastewater.
In Bangladesh, water quality has deteriorated in some locations as a result of pollution from agrochemicals, industrial waste and other sources and arsenic contamination of groundwater has been reported in many documents. In Cambodia, groundwater quality is generally satisfactory. However, unpalatably high iron levels are encountered in about 10 percent of the tubewells. In China, serious pollution occurs widely throughout every river system, not one single river is clean and more than half of the groundwater resources have been severely contaminated. Municipal wastewater discharges have surpassed industrial discharges since 2000, and have become the most important pollution source. Rural areas have also witnessed an increase in pollution caused by the inappropriate use of chemical pesticides and fertilizers.
In India, the upper reaches of most rivers are of good quality, while the lack of wastewater treatment plants in the middle and lower reaches of most rivers cause a major degradation of surface water quality. Groundwater quality is also affected by municipal, industrial and agricultural pollutants and the mobilization of arsenic from the Ganges-Brahmaputra sediments. In Indonesia, many rivers are significantly or seriously polluted owing to the high level of municipal and industrial waste and pollution. This is so severe in major cities that industries have been forced to close during dry years because of raw water shortages. In Malaysia, the main sources of organic water pollution are municipal and industrial sewage, effluent from palm oil mills, rubber factories and animal husbandry. In the Maldives, mostly because of tourism, the quantity of water drawn from Male’s aquifer during the 1970s increased tremendously and the increased amount of sewage being disposed ofinto the ground made it more susceptible to groundwater pollution. The increased volumes of groundwater being used to flush toilets were no longer returning to the aquifer but were being discharged to the sea, thus the salinity of the aquifer increased sharply limiting its usefulness as a resource.
Freshwater ecosystems of Mongolia are subject to increasing and multiplying threats, including overgrazing, dams and irrigation systems, growing urbanization, mining and gravel extraction, impact of climate change and lack of water management policies and institutional framework. In Myanmar, in the lower courses of rivers, sedimentation is one of the major adverse effects of storage dams. In Pakistan, indiscriminate and unplanned disposal of effluents (including agricultural drainage water, municipal and industrial wastewater) into rivers, canals and drains is causing deterioration of water quality in the downstream Indus river. The groundwater is marginal to brackish in quality in 60 percent of the aquifer of the Indus Basin Irrigation System (IBIS). In Thailand, surface water quality classified as ‘good’, ‘fair’ and ‘poor’ accounted for 48, 32 and 20 percent respectively in 2004. In Viet Nam, there is an ever-increasing pollution level of surface water, groundwater and coastal waters. Untreated industrial wastewater discharging into rivers is the main source of the pollution.
Sewage coverage is very low in most countries of the region. In Cambodia, India, Papua New Guinea (costal area of Port Moresby) and the Philippines it is reported that most of the wastewater flows into the receiving waters without any treatment.
On the other hand, Lao People’s Democratic Republic reports that the water quality of rivers within the country and the Mekong is considered to be good based on international standards. However, with the pressure of rapid demographic growth, socio-economic development and urbanization the water quality is increasingly exposed to deterioration. In Sri Lanka, the quality of the groundwater is generally fairly good and relatively constant throughout the year. However, in some parts of the country (northern and northwestern coastal areas) excessive concentrations of iron and nitrates (from agrochemicals and fertilizers) have been reported. Timor-Leste does not suffer from the problems of industrialization and farmers almost never use agrochemicals.
Careful management of surface water and groundwater withdrawal is required in the countries of the Southern and Eastern Asia region to avoid pollution and health problems. Some action plans and measures have been adopted to improve water quality and protect the environment. Brunei Darussalam, for example, has excellent facilities for the treatment of its drinking water at six government treatment plants situated throughout the country and two other private plants. There are also bottled water factories using advanced technology to produce purified water. Monitoring of treated water at treatment plants, storage points and end-points is carried out daily. The Democratic People’s Republic of Korea is applying knowledge on sustainable development of upland water catchments and use of marginal agricultural land to help reduce soil erosion and protect natural resources.
In India, the pollution control action plan of the Ganges river basin was formulated in 1984, to oversee pollution control and the consequent cleaning of the Ganges river. Similar programmes for other rivers have also been developed. In Maldives, desalination has become one of the few options available for providing sufficient safe water for Male. In Myanmar, the government is emphasizing the implementation of the terrace farming system to reduce shifting cultivation. In Nepal, the Environmental Action Plan of 1994 provided some guidelines for both Integrated Water Resources Management (IWRM) and maintaining the water quality at the river basin level.
In Papua New Guinea, sewerage systems were developed by Australia mainly in Port Moresby and urban cities from the 1960s to the early 1970s, before independence, in the inland area of Port Moresby and were also developed in 1999 and 2000 in the urban cities through a loan from the ADB. Japan financed a new project in 2010, called Port Moresby Sewerage System Upgrading, to develop sewerage facilities in the coastal area of Port Moresby. The Republic of Korea decided to implement a 15-year period (1996-2010) environmentally-friendly agriculture promotion plan to minimize pollutants coming from chemical fertilizers, agricultural chemicals, livestock and poultry waste, to maintain and improve agricultural resources including soil and water purity and to support farm households that practice environmentally-friendly agriculture.
The overexploitation of aquifers (when water withdrawal exceeds water recharge) and the subsequent lowering in their levels is a problem in some countries of the region. This overexploitation is the origin of seawater intrusion and/or the upward diffusion of deeper saline water in at least Bangladesh, China, India, Sri Lanka and Viet Nam, which leads to a deterioration of groundwater quality. Using saline groundwater for irrigation may increase soil salinity. The use of fossil water, which is water from aquifers with a very low rate of recharge, and which is therefore considered non-renewable, will cause depletion of the aquifers in the long term. In China, sea water intrusion has occurred in 72 locations along coastal provinces, covering an area of 142 km2 (World Bank, 2009). Intrusion of saltwater in deltas is a concern in Myanmar, Viet Nam and parts of India. Overexploitation of groundwater, also causes lowering of water tables, reduction in dry season flows of rivers and streams, groundwater pollution and ecological imbalance.
Salinization normally occurs in arid areas because of the low volume of rainwater dissolving the salts generated by the soil. 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. Consecutive accumulation of salts year after year degrades the soils and renders them unproductive.
Assessment of salinization at national level is difficult, 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 area salinized as a result of irrigation are available for eight of the 22 countries of which seven are from the previous survey, since no new information could be obtained (Table 27). In Bangladesh, the area salinized by irrigation was estimated at 100 000 ha in 1993. In Cambodia, increased salinity is seen in parts of the southernmost (delta) provinces, most likely owing to contamination by salt contained in the original deltaic deposits.
In China, the area salinized by irrigation was estimated at 6.7 million ha in 1999, though in recent years the area affected by salinization seems to have somewhat fallen. In India, the area salinized by irrigation was 3.3 million ha in 1998. In Indonesia, it is estimated that out of the total irrigated area about 400 000 million ha are affected by salinity. Salinization is also reported in the central dry zones of Myanmar, where major groundwater pumping irrigation schemes are located. In Pakistan, more than one-third of the irrigation area is reported to be affected by salinization. Soil salinity also constrains farmers and affects agricultural production. In the Philippines, the area salinized by irrigation was estimated at 300 000 ha in 1999. In Thailand, 10 percent of the irrigated land was affected by salt in the northeast of the country in 1999. Many programmes have been launched to correctly manage cash crops and paddy on saline soils. Salinization is now reported to be affecting large areas in the coastal parts of the central plain. In Viet Nam, the area salinized by irrigation was estimated at 300 000 ha in 1999.
Flooding and waterlogging
A large area of the Southern and Eastern Asia region is subject to flooding and waterlogging as reported for the following countries.
In Bangladesh, because of the low-lying topography, about 2.65 million ha or 18 percent of the country is inundated during the monsoon season each year. During severe floods the affected area may exceed 5.3 million ha or 37 percent of the country and, in extreme events such as the 1998 flood, about 66 percent of the country is inundated. Floods are caused by overspills from main rivers and their distributaries, overspills from tributaries and by direct rainfall. Of the total cropped area, about 1.32 million ha are severely flood-prone and 5.05 million ha are moderately flood-prone. In China, the area subject to waterlogging was 21.3 million ha in 2005. In northern China in particular waterlogging, salinization and alkalization have been the main constraints to agricultural production.
In India the area subject to flooding is estimated at about 40 million ha (about 12 percent of the area of the country). About 80 percent of this area, or 32 million ha, could be provided with reasonable protection. The state that is worst hit by floods is Bihar. With the onset of the monsoon, rivers come down from the Himalayan hills in Nepal with enormous force, causing the following rivers Ghagra, Kamla, Kosi, Bagmati, Gandak, Ganges, Falgu, Karmnasa, Mahanadi to rise above the danger level. The total area subject to waterlogging was estimated at 8.5 million ha in 1985, including both rainfed and irrigated areas. In Indonesia, flooding occurs during the rainy season, while drought is frequent in the dry season.
Massive deforestation and environmental degradation have resulted from these extreme conditions. In Mongolia, serious flooding of rivers was observed that caused severe property damage and loss of life. About 18 flood events were observed from 1996 to 1999, which resulted in loss of life and much property damage. In Pakistan, investments in drainage have been significant during the last two decades, though waterlogging still affects large tracts of land. Waterlogging in the Indus Basin Irrigation System was high in the 1990s as a result of heavy floods while droughts in the 2000–2005 period resulted in lowering of the water table and reduction in the waterlogged area.
In the Philippines, the main area subjected to floods is the central region of Luzon, namely the Pampanga, Zambales and Tarlac provinces. About 1 million ha have been identified as flood-prone areas. In Thailand, Bangkok faces problems of both too much and too little water. Flooding occurs frequently in the wet season owing to low average elevation, high tides and inadequate drainage. The Metropolitan Waterworks Authority is unable to supply water to meet all municipal and industrial demand. As a result, in the outskirts of Bangkok, private and industrial abstraction of groundwater exceeds the safe yield of the aquifer. This accelerates the rate of land subsidence (5-10 cm/year), which in turn aggravates the problem of flooding. Indeed, subsidence has caused some parts of the drainage systems to be below the normal water level and has thus rendered them ineffective. In Timor-Leste, rains can bring with them large-scale flooding, which washes pollution into the waterways. This water quality is often poor. Flooding is an annual event in northern Viet Nam and the cause of enormous losses. With as much as 80 percent of the population living on the coastal plains and deltas, costs incurred from floods and typhoons are colossal. Also there is immense loss of life, homesteads and general suffering of the people.
Drainage and flood control
One of the measures needed to prevent irrigation-induced waterlogging and salinization is the installation of drainage facilities. Figures on drained areas are available for ten of the 22 countries of which seven are from the previous survey, since no new information could be obtained (Table 28). Only five countries provide figures on the area equipped for irrigation that has been provided with drainage facilities, varying from 3 percent in Bangladesh to 95 percent in the Philippines.
In most of Southern and Eastern Asia, drainage is closely linked to irrigation. In traditional terraced paddy cultivation, water flows from one plot to another and no distinction can be made between irrigation and drainage. Bhutan, China, the Philippines and Viet Nam have specifically mentioned this type of drainage but it can apply to most of the areas where paddy rice is cultivated.
In several humid countries of the region, large segments of lowland or wetland are used for paddy cultivation. In such cases, while these areas are generally or usually accounted for as irrigated land, the main purpose of water control is to ensure appropriate control of water level and drainage. Typologies differ from one country to another to indicate very similar situations. Bangladesh and Cambodia use the terms controlled flooding or inundation, which are typical of paddy cultivation in the major deltas (Brahmaputra, Mekong). Lao People’s Democratic Republic reports on lowland flooded rice.
In these areas, drainage and flood control are also very much related. In Bangladesh, a master plan for water resources development was initiated in 1964, which envisaged the creation of 58 flood protection and drainage projects covering about 5.8 million ha of land. Flood control and drainage projects represent about half of the funds spent on water development projects since 1960. In 1993, the total area of wetlands was 3.14 million ha, of which 1.55 million ha were cultivated and 1.38 million ha were drained by surface drains. The flood protected area in 1990 was estimated at 4.2 million ha. Brunei Darussalam is working towards improving the irrigation system and has already introduced dykes and drainage systems to improve the water flow into and out of the fields.
The extreme case of agriculture under flood conditions is floating rice, which is reported in Cambodia, but can probably be found in other countries of the subregion. In Indonesia, total drained area was estimated at 3.35 million ha in 1990. In Lao People’s Democratic Republic, drainage and flood protection structures have generally been considered in the design plan of the irrigated schemes but have not been implemented often because of budget restrictions. A specific case of drainage is reported for Malaysia where 940 000 ha were drained in 1994, of which 600 000 ha for oil palm cultivation. In that year, the area equipped for irrigation drained accounted for 340 600 ha and flood protected areas were estimated at 840 000 ha.
In Myanmar, in the Ayeyarwady Delta drainage and flood control structures are also linked: in 1995 a total of 193 000 ha were reported to be equipped for surface drainage, which is considered as a form of flood protection. In 2006, the drainage systems covered 2.54 million ha, mostly in the northern and central parts of the country, particularly the Red River Delta. When the Indus Basin Irrigation System was developed in Pakistan, the drainage needs were initially minimal. They, however, increased over time as more irrigation water was diverted and the groundwater table rose to harmful levels causing waterlogging and salinity. The drainage systems have mostly been developed over the last 30-40 years. In 2008, the total drained area, all equipped for irrigation, was estimated at 15.14 million ha. In most schemes in the Philippines, drainage water from one field goes into another field downstream either through the irrigation canal or directly. In 1993, total drained area was estimated at about 1.47 million ha. Total drained area in the Republic of Korea was 1 million ha in 1996. In the wet zone of Sri Lanka, flood control and drainage schemes have been incorporated into the irrigation system mainly in the lower reaches of rivers.
Data on drainage infrastructure associated to irrigation in arid and semi-arid areas mostly concern northern China, India and Mongolia. In China as a whole (it was not possible to make a distinction between arid and humid areas), in 1996 it was estimated that 24.6 million ha were subject to waterlogging, of which 20.3 million ha were controlled by drainage. In 1995, the power drained area was 4.2 million ha, while in 2006 it was estimated at 4.5 million ha. In 2005, flood protected areas were estimated at 44 million ha. In India, drainage works have been undertaken on about 5.8 million ha (12 percent of the irrigated area) in 1991, but investment in drainage works associated with irrigation schemes has been widely neglected and where such investment has been made, poor maintenance has caused many drainage systems to become silted up. In 2010, only some irrigation systems, predominantly in south and western India, have well laid out drainage systems. No data were available for Mongolia.
Health and water-related diseases
Only 13 out of the 22 countries of the Southern and Eastern Asia region have reported on water-related diseases for this survey, although these diseases are certainly also present in the other countries of the region. The major factors favouring the development and dispersion of these diseases are as follows:
In Bangladesh some diseases and health hazards such as arsenicosis, blindness, physical disability, occur as a result of arsenic toxicity to humans (RDA, 2001). Brunei Darussalam has been declared malaria-free by WHO in 1987, though some new cases were reported in 2003, but they were all imported. Water supply- and sanitation-related diseases such as diarrhoeal diseases, hepatitis, cholera and typhoid have also occurred in Brunei Darussalam (WHO, 2004). In Cambodia malaria is a serious problem throughout the country because of the natural ecosystem. In 1999, estimates of about 500 000 cases of malaria per year were common, and approximately 5 000-10 000 people die from malaria each year.
Schistosomiasis (bilharzia) was reported in the Kratie area in 1993. Dengue haemorrhagic fever became a significant cause of child morbidity in the 1990s, about 7 000 cases resulting in 340 deaths were recorded that year. In rural China, the economic cost of disease and premature deaths associated with the excessive incidence of diarrhoea and cancer was estimated at 0.49 percent of the GDP in 2003 (World Bank, 2009). Above the Huang river, for example, abnormally high rates of mental retardation, stunting, and development diseases have been linked to the natural presence of arsenic and lead in the water. In Shanxi province, around the Huang river, high levels of lead and chromium were found in rice and cadmium in cabbages (Burke, 2000).
In India, water-related diseases have continued to increase over the years in spite of government efforts to combat them. States such as Punjab, Haryana, Andhra Pradesh and Uttar Pradesh are endemic for malaria because of the high groundwater table, waterlogging and seepage into the canal catchment area. There are also numerous cases of filariasis. In 1998, the population affected by water-related diseases was 44 million inhabitants. In Maldives, water-related diseases such as diarrhoea, cholera, shigella and typhoid started spreading as a result of poor sanitary conditions. In Mongolia, infections such as dysentery and hepatitis stem from a lack of access to safe water and sanitation infrastructure (UN, 2006).
In Pakistan, around 25 percent of all illnesses diagnosed at public hospitals and dispensaries are gastro-enteric and 40 percent of all deaths, 60 percent of infants’ deaths are caused by infections and parasitic diseases, most of them are water related. The most common diseases are diarrhoea, dysentery, typhoid, hepatitis, kidney stones, skin disease and malaria. In Papua New Guinea, the ratio of water-related diseases in the coastal area is higher than in other areas. Average diarrheal morbidity is 31 percent in the coastal area, while 5 percent in the city. In the Philippines, the population affected by water-related diseases in 2000 was more than 850 000. In Sri Lanka, large water development projects have increased the malariogenic potential of areas through increased vector propagation, aggregation of labour and resettlement from non-malarious areas of people with no immunity.
In Thailand, the main water-related diseases were acute diarrhoea (affecting 1.48 percent of the population) dysentery (0.14 percent) and enteric fever (0.03 percent) in 1999. Malaria, as a water-related disease, affected 0.12 percent of the population. Leptospirosis seems to prevail in flood-prone and irrigation areas, but is under control. There are no clear impacts (positive or negative) of irrigation on health. This is probably because of the complicated interaction among socio-economic factors and land-use changes. People whose rice is in irrigation areas are better off economically than those in rainfed areas and hence can afford better health care.
Changes in land use transform remote irrigation areas into suburban areas with reasonable road access. There is less poverty in areas that are irrigated than in rainfed. In Viet Nam, water-related diseases are still a major problem, although improvements are made in providing safe water to the urban and rural populations. Dysentery and diarrhoea are widespread. In four recent years about 6 million cases of six water-related diseases were incurring a direct cost of at least US$27 million for treatment of cholera, typhoid, dysentery and malaria.
Climate change is expected to have significant impacts in the Southern and Eastern Asia region. It may alter the distribution and quality of the region´s water resources. Some of the impacts include the occurrence of more intense rains, changed spatial and temporal distribution of rainfall, higher runoff generation, low groundwater recharge, melting of glaciers, changes in evaporative demands and water use patterns in the agricultural, municipal and industrial sectors, etc. These impacts lead to severe influences on the agricultural production and food security, ecology, biodiversity, river flows, floods, and droughts, water security, human and animal health and sea level rise.
Potential impacts on agriculture include vulnerability of crops to heat stress, possible shifts in spatial boundaries, of crops, changes in productivity potentials, changes in water availability and use, and changes in land use systems. Even a fractional rise in temperature could have serious adverse effects, such as a considerable increase in the growing degree days (GDD, which is a measure of heat accumulation used to predict the date that a flower will bloom or a crop reach maturity). This could not only affect the growth, maturity and productivity of crops, but would also require an additional amount of irrigation water to compensate the heat stress (Afzal, 1997; FAO, 2011c).
It is not the purpose of this survey to deal in detail with climate change issues. Much other research is being done specifically on this issue, which has resulted in many reports, such as FAO’s Water Report on “Climate change, water and food security”(FAO, 2011c).
PROSPECTS FOR AGRICULTURAL WATER MANAGEMENT
Countries in the Southern and Eastern Asia region consider water and irrigation management a key factor in the use and conservation of their water resources. In the future, agricultural water management in the countries of the Southern and Eastern Asia region, for which information is available, will take into consideration the following: Rehabilitation and modernization of the irrigation and drainage infrastructure, rehabilitation and construction of dams, increase of water use efficiency and recovery of the expenses for water supply service, reuse of water, integrated water resources management, establishment of more river basin organizations, improvement of water awareness and water education, flood and drought contingency plans, water quality management, strengthening of the institutions and policies for integrated water resources management, participatory approach in the decision-making process, innovative technologies, extensive research, water ecosystems protection and coordinated approach of governmental institutions, donors, NGOs and key stakeholder groups at river basin level. Developing water user associations is considered a priority in some countries.
Most countries of the region recognize the failure to develop adequate operation and maintenance mechanisms to ensure the sustainability of the irrigation schemes (mostly large, public schemes). Irrigation management transfer or increased user participation in the management of the schemes is seen by most countries as the solution to this sustainability problem. This is achieved through the development or improvement of water user associations (WUAs). The strengthening of WUAs is also linked to the need expressed in several countries to improve the overall performance and water use efficiency of irrigation schemes.
Water scarcity is another major issue mentioned in several country reports such as for China, Mongolia, the Philippines or India. Increased competition for water between sectors already affects agriculture in China, India, Malaysia, Thailand and the Republic of Korea and the trend is towards an intensification of the problem mainly because of the rapid growth of the municipal and industrial sectors in these countries. In China, the country level data hide massive regional differences in water scarcity behind the average figures. In 2030, the annual deficit at national level would be around 13 km3, but in the North China Plain it would be as high as 25-46 km3.
Water scarcity and the interdependency between water use sectors are pushing countries to develop integrated water resources management programmes. In Bangladesh, conflicts among alternative and competing uses of water are becoming sharper as the demand for water has been increasing. Thus it is necessary to formulate a long-term vision for integrated water resources management to address the demands of all water using sectors. In Indonesia, the government has proposed an Integrated Water Resources Management Policy framework to support water resources development and management. In Mongolia, there is an urgent need to consider implementing the Integrated River Basin Management (IRBM) principles for sustainable water management.
Water quality is also a growing concern in several countries, especially where industrial development is important: Republic of Korea, India, Malaysia, the Philippines. The increased importance of water conservation and protection in the national programmes is also mentioned in Indonesia, the Philippines and Bangladesh. In this last country, siltation is the single most important water quality issue.
Changes in rainfall pattern resulting from climate change will significantly disrupt the farmers cropping system particularly in rainfed areas. It will become more difficult and risky for farmers to just rely on rainfall for their planting calendar. Extreme climate events will likely impinge the hydrological system in most of the river basins and will mean that water is becoming either ‘too much’ or ‘too little’. When water becomes too much, the potential effects include flooding from overflowing rivers and excessive runoff from sloping lands damaging water infrastructure, such as dams, irrigation and drainage systems. At the other end, higher temperatures and decreased precipitation mean too little water, resulting in a decreased water supply and an increased water demand, which might cause deterioration in the quality of freshwater bodies.
There will be possible alterations in the distribution of surface water and groundwater resources resulting from changes in recharging and discharging patterns. Stream flows will be significantly reduced and groundwater levels will decline. To be able to deal with water scarcity, the demand and supply side of water management needs to be focussed on through rehabilitation of water sources, water conservation, and augmentation of water supply, including the optimum utilization of wastewater as an alternative water source for irrigation. To be able to deal with flooding and excessive runoff, the drainage facilities that immediately remove excess flood waters need to be improved. In the design of irrigation systems, a review of design methods should include the effects of climate change and incorporate properly designed drainage facilities to protect standing crops. The construction of rainwater harvesting structures (e.g. small water impounding project) to collect and store rainwater in the uplands could contribute to flood mitigations downstream and water availability during the dry season.
As the older public schemes in most countries soon reach 50 years, the issue of rehabilitation and modernization is becoming increasingly important. While for some countries (such as Lao People’s Democratic Republic, Myanmar, the Philippines, Viet Nam and parts of India) the extension of irrigated land still represents an important part of their irrigation programmes, in most countries rehabilitation and modernization programmes are gaining increasing importance. The increased land and water scarcity and low expected return of future expansion of irrigation in these countries are often factors explaining the growing importance of modernization in irrigation programmes.
Increasing water-use efficiency and productivity will be made possible if efficient pressurized irrigation techniques and irrigation scheduling is adopted. Increasing the net benefit per unit of land and water could be possible if the cultivation of crops with high water requirements is reduced. In India, to meet the estimate of food grain requirement by 2025, it is assumed that the overall irrigation efficiencies will be around 50 percent for surface water systems and 72 percent for groundwater systems, compared to the present level of 35-40 percent. In Thailand water management in agriculture is said to have to focus on improving water-use efficiency because (i) the trend indicates that Thailand’s water shortage is emerging; (ii) the agriculture sector consumes the largest proportion of water. In Sri Lanka, increasing irrigation efficiency is one of the feasible options available for meeting future water demand.
According to available information, the current use of non-conventional sources of water (desalination and/or direct use of treated wastewater and agricultural drainage water) only concerns seven out of the 22 countries in the region, representing less than 1 percent of the region’s total withdrawals. Non-conventional sources of water, in general, are not included as a priority in the water management plans and policies of the countries of the region. Though, these sources of water are expected to develop in the future, as reported at least by Bhutan and the Maldives. It should also be mentioned that agricultural drainage water is already directly reused in many rice growing areas where water flows on terraces from one plot to another lower lying plot (cascades). Detailed information on quantities is, however, not available.
Financial sustainability requires a revision of measurement, computation and recovery mechanisms related to water fees. In countries such as China, India, Lao People’s Democratic Republic, Thailand, the policy is now to adjust water fees so that they cover at least the cost of operation and maintenance. In India the water rates shall be linked directly to the quality of service provided.
Major inter-basin transfer programmes are reported in China and Thailand.
Riparian countries sharing transboundary river basins need to prepare joint water management plans for each basin to ensure clear communication, so as to avoid conflicting approaches, unilateral development, and inefficient water management practices that may cause international crisis in these countries.
While irrigation has been instrumental in achieving self-sufficiency in staple crop production in recent decades in most countries of the region, some countries still indicate self-sufficiency as a major target of their irrigation development programmes; this is mainly to keep pace with rising populations. In Bangladesh, the expansion of irrigation coverage would reach its maximum potential limit by 2025. However, the rate of increase in water demand is expected to register a declining trend in response to demand management practices such as conservation, water-use efficiency, recycling. Cambodia is working to increase investment in irrigation and research to promote agricultural production for poverty reduction and the government has shown a strong commitment to increasing the irrigated area by 20 000 ha per year. In Myanmar irrigation will have to play a major role in the development of the agriculture sector, since the government’s objective is to achieve a surplus in rice production, self-sufficiency in edible oil and to set up the production of exportable pulses and industrial crops. In Timor-Leste, it is felt that the production of higher value crops, associated with some form of processing, are the next stage in the development of the agriculture sector.
Information is available for some countries regarding specific water plans for the future. In Lao People’s Democratic Republic, the Asian Development Bank and World Bank in 2006 undertook studies to define the scope of an integrated water resources management strengthening programme in the country. Myanmar plans to implement a project on “Strengthening farmers’ irrigation management”, with technical assistance from the Japanese Government. The objective is to reduce the government’s administrative and maintenance costs of new irrigation projects as well as those of existing irrigation systems. In Timor-Leste, the Strategic Development Plan (2010-2020), defines the working plan related to agricultural water management.
MAIN SOURCES OF GENERAL INFORMATION
Documents cited in this section were useful in the writing of the summary and are not specific to a country or river basin. Literature relative to the individual countries is listed in the section “Main sources of information” at the end of each country and river basin profile.
Afzal, M. 1997. Global agenda for livestock research, Pakistan paper. Proceedings of a consultation on setting livestock research priorities in West Asia and North Africa (WANA) Region. 12-16 November 1997, International Center for Agricultural Research in the Dry Areas. Aleppo, Syria.
Ahmad, S. 2008. Scenarios of surface and groundwater availability in the Indus Basin Irrigation System (IBIS) and planning for future agriculture. Paper contributed to the Report of the Sub-Committee on: Water and Climate Change. Taskforce on food security 2009, Planning Commission of Pakistan.
Ahmed, M. Feroze. 2007. Integrated water resources management in Bangladesh. RSS Workshop on IWRM, Bangladesh University of Engineering & Technology, Dhaka.
Bangladesh Agricultural Development Corporation. 2006. Groundwater zoning map and its application. A National Seminar Paper presented by Eftekharul Alam, 9 April, Sech Bhaban, Dhaka.
Bhutta, M.N. 1999. Vision on water for food and agriculture: Pakistan’s perspective. Regional South Asia Meeting on Water for Food and Agriculture Development. New Delhi.
Bhutta, M.N. & Smedema, L.K. 2005. Drainage and salinity management. Country Water Resources Assistance Strategy Background Paper No. 15 March 2005.
Burke, M. 2000. Managing China’s water resources. Environmental Science & Technology - News. 1 May 2000.
Cambodia's Development Policy Research Institute. 2008. Framing research on water resources management and governance in Cambodia: a literature review. Working paper 37.
Central Intelligence Agency - United States. 2010. Factbook, country profiles.
Columbia University. 2007. Asia: Population, culture and economy.
FAO. 1995. Irrigation in Africa in figures/L'irrigation en Afrique en chiffres. FAO Water Report No. 7. Rome.
FAO. 1997a. Irrigation in the Near East Region in figures. FAO Water Report No. 9. Rome.
FAO. 1997b. Irrigation in the countries of the former Soviet Union in figures. FAO Water Report No. 15. Rome.
FAO. 1997c. Irrigation potential in Africa - a basin approach. FAO Land and Water Bulletin No. 4. Rome.
FAO. 1999. Irrigation in Asia in figures. FAO Water Report No. 18. Rome.
FAO. 2000. Irrigation in Latin America and the Caribbean in figures. FAO Water Report No. 20. Rome.
FAO. 2003. Review of world water resources by country. FAO Water Report No. 23. Rome.
FAO. 2005. Irrigation in Africa in figures - AQUASTAT survey 2005. FAO Water Report No. 29. Rome.
FAO. 2009. Irrigation in the Middle East region in figures - AQUASTAT survey 2008. FAO Water Report No. 34. Rome.
FAO. 2011a. FAOSTAT - database. (http://faostat.fao.org/).
FAO. 2011b. AQUASTAT - database. (http://www.fao.org/nr/aquastat/).
FAO. 2011c. Climate change, water and food security. FAO Water Report No. 36. Rome.
Government of Pakistan. 2008. Agriculture statistics of Pakistan. Economic Wing of the Ministry of Food, Agriculture and Livestock, Government of Pakistan.
India Waterportal. No year. Indus River Basin: an overview. Website accessed on 02/02/2011).
Inidanetzone. 2010. Indus River. Website accessed on 09/02/2011).
International Rivers Network. China's Nu River. Dam projects threaten magnificent world heritage site. (Website accessed on 23/02/2011).
International Waterlogging & Salinity Research Institute. 1997. Integrated surface and groundwater management programme for Pakistan. Surface Water Interim Report No. 98/1.
Kijne, J.W. & Kuper, M. 1995. Salinity and sodicity in Pakistan's Punjab: A threat to sustainability of irrigated agriculture. Water Resources Development, Vol. 11.
National Disaster Management Authority - United Nations Development Programme. 2010. Pakistan Indus River System. Five-day training course on: Flood Mitigation.
Pakistan Water Partnership. 2000. Framework for action for achieving the Pakistan Water Vision 2025. Pakistan Water Partnership. 75 p.
Press Information Bureau, Government of India. 2008. Prime Minister's opening remarks at the Press Conference. 10 October 2008 (Release ID: 43550).
Qazilbash, I. A. 2005. Water and energy. Country Water Resources Assistance Strategy Background Paper No. 4, March 2005.
Rural Development Academy. 2001. Safe drinking water supply through RDA-developed low-cost deep tubewell. A Report prepared by M.A. Matin, M.H. Khan and M.N.I. Khan, RDA, Bogra, November 2001.
The Hindu. 2007. Baglihar dam: India claims moral victory. Website accessed on 09/02/2011).
The Millenium Project. 2010. Environmental Change and Biodiversity.
United Nations Development Programme. 2011. Human Development Index. (http://hdr.undp.org).
United Nations Children's Fund/World Health Organization. 2010. Joint Monitoring Programme (JMP) for water and sanitation. (http://www.wssinfo.org).
UN-Water. 2006. The Second United Nations World Water Development Report: 'Water, a shared responsibility'.
UN-Water. 2009. The Third United Nations World Water Development Report: 'Water in a changing world'.
Water Aid. 2000. An overview of the arsenic issues in Bangladesh. Edited by M. Jones Elizabeth, Water Aid Bangladesh, Dhaka.
Water Environment Partnership in Asia. State of water environmental issues: Cambodia. Website accessed on: 02/12/2010.
Water and Power Development Authority. 2006. Salinity & Reclamation Directorate, SCARP Monitoring Organization (SMO). WAPDA, Lahore.
World Bank. 2005. Country Assistance Strategy. Pakistan's economy running dry. World Bank, Pakistan Resident Mission, Islamabad.
World Bank. 2009. Addressing China’s water scarcity. Washington, DC.
World Bank. 2010. Indicators of world development. Available at http://www.worldbank.org/. Washington, DC.
World Commission on Dams. 2000. Tarbela Dam and related aspects of the Indus River Basin in Pakistan.
World and its peoples. 2007. Myanmar and Thailand.
World Health Organization. 2004. Brunei Darussalam environmental health country profile. (Accessed on: 25/02/2011).
World Rainforest Movement. 2003. Laos: Villagers mount unprecedented protest against dam in Laos.
WRRI, MONA & IIMI. 1999. Spatial analysis of the groundwater in SCARP areas. A Case Study of the MONA Unit.Water Resources Research Institute, MONA Reclamation Experimental Project and IIMI, Islamabad.
Zakria, V. 2000. Water and environment sustainability. Country Water Assistance Strategy, Background Paper No. 3, Islamabad, Pakistan.
Zaman, S.B. & Ahmad, S. 2009. Salinity and waterlogging in the Indus Basin of Pakistan: Economic loss to agricultural economy. A series of NRD Research Briefing, PARC, Islamabad.
The following summary tables are available for the Southern and Eastern Asia region:
Table 29- Land use and irrigation potential
Table 33- Water withdrawals by source
Table 36- Full control irrigation techniques
Table 37- Origin of full control irrigation water
The following regional figures are available for the Southern and Eastern Asia region:
Figure 3: Regional division of the world adopted by AQUASTAT
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