Environmental performance reviews united nations
PART III: INTEGRATION OF ENVIRONMENTAL
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- Chapter 6 SUSTAINABLE MANAGEMENT AND PROTECTION OF WATER RESOURCES 6.1 Introduction
- River basin S tem stream S mall Total
- River Recommended for collector- drainage use Available water resources Groundwater
- Table 6.2: Groundwater reserves and use, million m 3 /year
- Table 6.3: Water resources use average, 2002–2006 Water resources use km 3 % Total, including: 55.1 100
PART III: INTEGRATION OF ENVIRONMENTAL
CONCERNS INTO ECONOMIC SECTORS AND PROMOTION OF SUSTAINABLE DEVELOPMENT 87 Chapter 6 SUSTAINABLE MANAGEMENT AND PROTECTION OF WATER RESOURCES 6.1 Introduction Uzbekistan and the majority of its neighbouring countries are situated in the Aral Sea internal drainage basin, where they share transboundary waters. The scarcity of freshwater is currently, and will be in the future, the greatest environmental problem, since water is the key resource for irrigating low productivity saline lands for agricultural production. In-stream disposal of collector–drainage waters and inefficient wastewater purification systems result in a deterioration of water resources quality and an increase in water salinity. With respect to the availability of water resources, Uzbekistan is located in quite unfavourable natural conditions. The hydrographical network of Central Asia has a very uneven distribution of water bodies and resources. Since only about 10 per cent of the water resources are generated in the country, Uzbekistan is highly dependent on the inflow of waters from its neighbouring countries. The utilization of water resources without taking into account the environmental capacity has also resulted in water quality deterioration and a tense situation concerning drinking water supply. Coinciding with the second Environmental Performance Review (EPR) of Uzbekistan, the theme of the United Nations World Water Day 2009 was “Shared Water – Shared Opportunities”, with particular emphasis on transboundary waters, which is drawing attention to one of the most alarming water crises not only in central Asia, but in the world – the Aral Sea catastrophe, partly caused by the water management in the Aral Sea basin of recent decades. The reasons for and consequences of the Aral Sea catastrophe are well known. The drying-up of the Aral Sea has been accompanied by a wide range of other environmental, economic and social problems in the basin, which led to a variety of diseases emerging or becoming increasingly common among the inhabitants, the degradation of valuable farmland, traffic routes and residential areas, unemployment, impoverishment and migration. 6.2 Water resources The distribution of water resources in the Aral Sea internal drainage basin is extremely uneven and determined by different surface flow generation conditions that are favourable in the mountainous areas and unfavourable in vast plain areas occupied by deserts and semi-deserts. The largest amount of surface water resources (about 90 per cent) is generated in the mountainous areas of neighbouring countries. Internal water resources comprise lakes, groundwater resources, rivers and the water reserves of glaciers. Large and small rivers, as well as groundwater, are the main constituents of available water resources in Uzbekistan (table 6.1). The main rivers are the Amu Darya River, formed by the confluence of the Vakhsh and Pyandj Rivers, the Syr Darya River, formed by the confluence of the Narin and Karadarya rivers, and the Chirchik River near Tashkent. The Amu Darya River basin includes the Surkhandarya, Sherabad, Kashkadarya and Zarafshan rivers, but only the Kashkadarya and Sherabad Rivers are entirely located within the territory of Uzbekistan. In addition to the main rivers, there are over 17.7 thousand natural water streams in Uzbekistan. The Amu Darya River delta, with an area of 700,000 ha, is a natural wetland system and has been significantly changed by the Aral Sea crisis. Surface water The Aral Sea and its littoral zone is served by an annual inflow from transboundary watercourses within the approved water intake limits of not less than 14.5 km 3 /year. This represents 10 km 3 /year for the Amu Darya River and 4.5 km 3 /year for the Syr Darya River. Compliance with these limits depends on water availability in a given year as well as the ability to implement measures aimed at the rational 88 Part III: Environmental concerns in economic sectors and sustainable development use of water by users. To protect the delta and coastal ecosystems from the threat of damage, Uzbekistan envisaged the creation of artificially regulated ponds to replace the former littoral and intra-delta lakes and sea bays, along with a set of forest amelioration measures. For this purpose, it is planned that up to 3.0 km 3 of the country’s available water in an average year will be released from the Amu Darya River downstream of the Kzyldjar site. The amount of released water varies between 0.5 and 4 km 3 /year (2005) due to water availability. There are approximately 500 lakes in Uzbekistan. They are mainly small water bodies with an area of less than 1 km 2 . Only 32 lakes have a surface exceeding 10 km 2 . Winter discharges of water from the Toktogul Reservoir resulted in increasing the area of the Aydar Arnasay Lakes System, which is now the largest in Uzbekistan. With its area of 3,600 km 2 and its storage capacity of 42 km 3 , this lake exceeds the water reserves of all other reservoirs. In 2008, it was added to the list of the Ramsar Convention on Wetlands of International Importance Especially as Waterfowl Habitat. Reservoirs play a very important role in the operation of water management systems in Uzbekistan, adding to the capacity to cope with variability (hydrological extremes) and to control water resources. Currently, there are 51 operating reservoirs in the country, which are mainly used for irrigation purposes. Uzbekistan’s largest reservoirs have multipurpose uses and are intended mainly for irrigation, power engineering and industrial needs. The total rated storage capacity of these reservoirs is 18.8 km 3 , and the active storage capacity is 14.8 km 3 . These man-made wetland ecosystems are used for fishing. The ecological problems of wetlands are caused by the unstable regime of water inflow and the fact that they are poorly protected. As a result, there are only limited possibilities to conserve the habitat and biodiversity of this ecosystem. River basin S tem stream S mall Total Syr Darya 10,490 9,425 19,915 1,590 2,600 24,105 Amu Darya 22,080 10,413 32,493 301 2,310 35,104 Total for Uzbekistan 32,570 19,838 52,408 1,891 4,910 59,209 River Recommended for collector- drainage use Available water resources Groundwater Table 6.1: Breakdown of currently available water resources, million m 3 Source: State Committee for Nature Protection, 2008. Groundwater The estimated regional groundwater reserves in Uzbekistan make up 18,455 million m 3 /year. The total actual extraction is 7,749 million m 3 /year, which is about 42 per cent of the estimated reserves (table 6.2). The total volume of natural groundwater in Uzbekistan is estimated to be 24.35 km 3 . Out of this amount, 20.79 km 3 lies in the Quaternary deposit, 2.92 km 3 in the Upper Pliocene–Quaternary deposit, and 0.46 km 3 in the Upper Cretaceous deposit. Fresh groundwater is concentrated mainly in the Fergana Valley (34.5 per cent) and the regions of Tashkent (25.7 per cent), Samarkand (18 per cent), Surkhandarya (9 per cent) and Kashkadarya (5.5 per cent), with the rest being brackish or saline and having limited potential for use. For the remaining areas, the freshwater total is about 7 per cent. Currently, the groundwater resources of Uzbekistan can provide about 64 million m 3 /day. The balance between groundwater extraction and formation in the centralized extraction areas is observed by monitoring wells. The trend in groundwater abstraction has increased from 13.45 million m 3 /day in 2001 to 18.19 million m 3 /day in 2008, with 120 cities and district centres covered. Owing to reorganization and new automatic devices, the number of observation stations was reduced by 40 per cent (from 1,850 to 1,074) in 2001. The regional assessment also covers transboundary aquifers from the Central Asian countries. Although the studies have not been completed, 19 aquifers with significant resources have been reported as transboundary, bordering or shared by two or more countries. Twelve of them are shared by Uzbekistan and its neighbours. Transboundary groundwater plays a significant role in the region. Chapter 6: Sustainable management and protection of water resources 89 Since 2001, the observation of these 12 transboundary aquifers has become increasingly of interest. The impact of industry on the transboundary groundwater resources in Uzbekistan, Kyrgyzstan and Tajikistan is observed by 12 observation stations. 6.3 Water quality and monitoring Considering the close relationship between environmental conditions and water availability, many national indicators have been developed for the assessment of water quality. Twenty-five ecological indicators and ten subindicators are used to assess the changes in the state of water resources, water consumption volumes in different economic branches, streamflow deficit rate and quality change patterns of surface water and groundwater. Surface water quality The pollution of surface water bodies is widespread and results in the considerable pollution of groundwater, including the water in wells. Water pollution plays a determining role in the increase in morbidity rate (kidney disease, oncological and acute infectious diseases), resulting in increased adult and child mortality rates. Anthropogenic impacts also result in soil pollution (salinity, toxic pollution, pesticides, residual quantities of fertilizers and heavy metal pollution) and affects public health. The current quality of the country’s water resources remains extremely unsatisfactory. The highest level of mineralization and pollution is observed in the middle and lower reaches of the main rivers. This presents a serious threat to the life and health of the population and to the conservation of habitats. Polluted water comes from irrigated agriculture (78 Estimated regional groundwater reserves 18,455 Reserves confirmed for extraction 7,796 Total actual extraction 7,749 Domestic water sup p ly 3,369 Industry 715 Irrigation 2,156 Vertical drainage wells 1,349 Pumping tests 120 Other 40 Table 6.2: Groundwater reserves and use, million m 3 /year Source: CAWATERinfo, http://www.cawater-info. net/aral/groundwater_e.htm (accessed in August 2009) per cent), industry (18 per cent) and the municipal sector (4 per cent). Agriculture is the main polluter of surface water and groundwater. Although industrial effluents are slightly smaller in volume, they are more dangerous and harmful because of their level of toxicity. The water pollution index (WPI) is used for the integrated assessment of water quality. The WPI calculates the arithmetic mean value of six hydrochemical indices expressed as fractions of the maximum allowable concentration (MAC). These indices are the content of dissolved oxygen, biochemical oxygen demand (BOD) and any other four pollutants with the highest above average concentrations. There are seven classes of water quality according to the WPI, from I (very clean, WPI < 0.3) to VII (extremely dirty, WPI > 10). Overuse of agrochemicals (nitrates, phosphates, pesticides) results in the intensive pollution of agricultural lands and water resources, from the irrigated fields into collector–drainage waters. Their concentration in collector water exceeds the MAC values for domestic/drinking water supplies by 5 to 10 times. The analysis of available information indicates that the WPI for almost all water for the last three years has changed little and is consistent with the water quality class III (moderately polluted). A small number of water bodies corresponded to the Class II water category (clean). These include the Chatkal, Ugam, Aktashsay, Kyzylcha and Chimgansay Rivers in different years ranging from Class II (clean) to Class III (moderately polluted) due to heavy anthropogenic pressures in the Chimgan tract. Groundwater quality In the east of Uzbekistan, 60 per cent of the total water reserves are underground. In all but a few areas, this water meets the Uzbek 2000 state standard (O´z DST) 950 on drinking water. Groundwater reserves in the western part of the country (in the lower reaches of the Zarafshan River and the western part of the Kashkadarya, Syr Darya, Amu Darya and Central Kyzyl Kum basins) are highly mineralized and hard. The fresh groundwater lenses formed along the large watercourses (Amu Darya River and irrigation canals) and used to supply drinking water to the Khorezm region and the Republic of Karakalpakstan do not meet national 90 Part III: Environmental concerns in economic sectors and sustainable development standards due to an increase in the last 10 to 15 years in mineralization and hardness (the effects of irrigation). Around 50 per cent of the total volume of groundwater extraction in the country takes place in the Fergana Valley. As in the other regions, the depletion of underground reserves and degradation of their quality due to anthropogenic impact are typical. In order to better protect current and potential sources of drinking water in the country, the status of “area of national environmental importance” has been given to eleven zones of fresh groundwater formation. As a result of anthropogenic factors, the groundwater quality continues to deteriorate in some regions of the country, such as the Republic of Karakalpakstan. One hundred and forty hydrogeological stations in almost all regions have observed the state of groundwater since 1995. The monitoring system covers 99 national groundwater deposits, reservoirs and tail systems, 1,671 wells and 43 springs and includes 1,074 observation stations with automatic devices. Also, groundwater extraction is monitored for 7,000 major water users for different purposes (drinking water, industry and irrigation), with the supply network comprising 45,000 wells, 28,800 of which are functioning and pumping 17.7 million m 3 / year. Since 2001, the investments in groundwater monitoring and exploration have increased by 15–20 per cent per year, all covered by a long-term programme fully funded by the State (chapter 3). Drinking water is analysed according to the Uzbek 2000 state standard (O´z DST) on drinking water using modern equipment such as atom absorption spectroscopy, high performance liquid chromatography and enzymatic analysis (polymerase chain reaction). For substances that can be analysed, the World Health Organization and MAC lists are used. Since 2001, additional MACs have been introduced for mercury and chromium. Out of the 133 mineral water wells with balneological activity, 119 have elevated concentrations of physiologically active compounds 1 , salts, gas compositions and higher temperatures, including 81 sites with proven operating reserves and 38 sites with probable stocks in 2005. These include resorts, sanatoriums, preventoriums, rest homes, physiotherapy clinics, factories and mineral water bottling plants. Not all of them are currently in operation, because a number of water facilities need repair and new technical equipment. 6.4 Water use and status of the water infrastructure In Uzbekistan, general water use is based on the shared use of transboundary and internal water resources of the Aral Sea basin, in accordance with the allocated approved limits, and varies between 45 and 62 km 3 /year depending on the dryness of the year. Over 90 per cent of this volume is used in irrigated farming (table 6.3). Consumer water use is based on the principle of equal water supply. Priorities in water delivery among the various sectors of the economy are as follows: Drinking and municipal water supply; • Industry; • Agricultural and rural water supply; • Water users approved by special government • decision; Sanitary releases to irrigation systems and small • rivers. Irrigation Out of the total volume of water, irrigation consumes about 90 per cent, with an annual consumption of 38.6–59.5 km 3 (2002–2008) depending on the availability of water resources. Taking into account 1 Bromine, boron, iodine-silicon, radon, hydrogen sulphide and iron. Source: State Committee for Nature Protection, 2008. Table 6.3: Water resources use average, 2002–2006 Water resources use km 3 % Total, including: 55.1 100 Irrigated farming 49.7 90.2 Non-irrigation users, including: 5.4 9.8 Domestic and drinking water supply 3.4 6.1 Industry 1.2 2.2 Fishing sector 0.8 1.5 Chapter 6: Sustainable management and protection of water resources 91 the importance of agriculture to the national economy and the fact that 16.579 million people in rural areas are directly dependent on water for their livelihood, incomes and welfare, it is extremely important to ensure an adequate water supply to this sector. Currently, the irrigation system of 4.3 million ha of land consists of 1,600 pump stations with a frequency range of 1 to 300 m 3 /s and 140,000 km of collectors, and requires an average of 57 km 3 of water annually. The irrational and inefficient use of water is the main factor restricting the development of irrigated agriculture. The main reasons for low efficiency are the significant losses through infiltration from the unlined main canals, on-farm irrigation networks and directly through field irrigation water application. Only a small fraction of the water taken from its source is used advantageously. Over recent years, the Cabinet of Ministers has adopted a number of measures aimed to increase the efficiency of the main canals, thereby improving water delivery. Optimal approaches to irrigation and water management mechanisms at various levels and in various regions of the country are being demonstrated by international organizations and donor countries. A combination of technical, water management and environment protection measures is envisaged in the irrigated agriculture sector. These include the reconstruction and maintenance of the irrigation and drainage network in order to reduce losses from canals and irrigated fields, water conservation and an increase in water availability in districts with low supply. About 60 billion sum (about US$ 41 million) are provided by the public budget for the rehabilitation and reconstruction of the main canals and pump stations. Under the “optimum” scenario (table 6.4), the efficiency of irrigation systems 2 should be increased to 0.70 by 2010 and 0.75 by 2025. The efficiency of irrigation water application methods 3 is planned to increase on average up to 0.69 in the near future, and up to 0.74 by 2025. Drinking water Groundwater is mainly used for domestic and drinking water supplies (173.5 m 3 /s), irrigation and stock water development needs (70.5 m 3 /s) and industrial and process water supplies (29.6 m 3 /s), as shown in figure 6.1. Groundwater resources provide 80 per cent of the drinking water supply to the population. In general, 2 The efficiency of irrigation systems involves various components and takes into account losses during storage, transport and application to irrigated plots. 3 Water application methods in Uzbekistan are as follows: surface irrigation; localized irrigation; drip irrigation; sprinkler or overhead irrigation; centre pivot irrigation; lateral move (side roll, wheel line) irrigation; subirrigation; and manual irrigation. SamAuto enterprise, Samarkand 92 Part III: Environmental concerns in economic sectors and sustainable development mill.ha km 3 mill.ha km 3 mill.ha km 3 mill.ha km 3 mill.ha km 3 mill.ha km 3 Amu Darya 2.3 37.0 2.6 34.0 2.9 33.0 2.3 27.0 2.9 35.0 3.9 39.0 Syr Darya 1.8 22.0 1.9 21.0 2.0 20.0 1.9 22.0 2.0 20.0 2.3 20.0 Total 4.1 59.0 4.5 55.0 4.9 53.0 4.2 49.0 4.9 55.0 6.2 59.0 Download 5.03 Kb. Do'stlaringiz bilan baham: |
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