Journal article (review)Free to read
Groundwater resources of Uzbekistan: an environmental and operational overview
https://doi.org/10.2478/s13533-011-0062-y
Highlights
- Groundwater resources: 23–27 km³ a year; 37% (about 10 km³) from subsurface inflow and precipitation, 63% from seepage from canals, reservoirs and irrigated land.
- Forecast regional reserves: 19.6 km³ a year — 7.32 km³ under 1 g/L (37%), 2.61 km³ at 1–1.5 g/L (13%), 7.42 km³ at 1.5–3 g/L (38%), 1.26 km³ at 3–5 g/L (7%) and 0.98 km³ over 5 g/L (5%).
- Duration of the water cycle: mountain hydrogeological massifs 0.95–2.6 years (2.1 on the Turan platform); intermountain depressions, valleys and piedmont fans 18–50 years (20–40); artesian reservoirs 95–640 years in the orogenic areas and 170–1,480 years on the Turan platform; desert freshwater lenses under 650 years.
- Abstraction: about 7.5 km³ a year against a limit of 6.8 km³. In 2004 withdrawal reached 216% of approved reserves in Kashkadarya, 206% in Surkhandarya, 193% in Bukhara and 163% in Syrdarya province; 88 aquifers were counted nationwide.
- Quality: fresh groundwater (under 1 g/L) has decreased by 40%; 35–38% of explored fresh reserves are polluted to some degree and cannot be used. In the lower Amu Darya the water table rose from 15–20 m in the 1980s to 1–1.5 m in the early 2000s.
- Aquifers shared with neighbouring countries: 11 — with Kyrgyzstan (4), Tajikistan (4), Kazakhstan (2, including the deep artesian Pretashkent aquifer) and Turkmenistan (1).
Keywords
- Central Asia
- salinization
- water management
- hydrogeology
- irrigation
- aquifer
Summary
This review covers the extent, quality and management of groundwater in Uzbekistan. About 80% of the country is desert and steppe, and its groundwater depends on the Pamir and Tien Shan, whose snow and glaciers feed the rivers and alluvial aquifers. Between 5% and 22.5% of precipitation recharges groundwater. The plains are covered by interbedded Quaternary and Pliocene sand, loam and clay that form confined or semi-confined aquifers in places; deep Cretaceous sandstones in the Aral Sea area hold artesian water, in parts too saline to use. Many shallow aquifers are salinized, at 1–10 g/L, while mineralization tends to fall with depth.
Estimates of the country’s groundwater resources range from 23 to 27 km³ a year. Only 37% comes from natural sources, subsurface inflow and precipitation; 63% is seepage from irrigation canals, reservoirs and irrigated fields. Regional reserves are assessed in 13 hydrogeological zones. Groundwater renews fastest in the fresh unconfined water of the river deltas, about 12% of the resources, and slowest in the artesian aquifers, 13% of the resources, where the water cycle lasts from 95 to 1,480 years. Intermountain depressions, river valleys and piedmont fans, with cycles of 18–50 years, hold the remaining 75%.
Groundwater makes up roughly 10% of Uzbekistan’s water resources and is used mainly for drinking-water supply, less for industry and irrigation. Abstraction, about 7.5 km³ a year, exceeds the limit of 6.8 km³, and in the arid southern provinces withdrawal runs at almost twice the approved reserves. Irrigation has raised water tables and salinized soils and groundwater: in the lower Amu Darya the water table rose from 15–20 m deep in the 1980s to 1–1.5 m in the early 2000s, and fresh groundwater with under 1 g/L of salts has decreased by 40%. Eleven aquifers are shared with neighbouring countries, among them the deep artesian Pretashkent aquifer with Kazakhstan. The authors call for a law specifically on groundwater.
How to cite
Shavkat Rakhmatullaev, Frédéric Huneau, Jusipbek Kazbekov, Hélène Celle-Jeanton, Mikael Motelica-Heino, Philippe Le Coustumer and Jamoljon Jumanov (2012). Groundwater resources of Uzbekistan: an environmental and operational overview. Central European Journal of Geosciences (now Open Geosciences), vol. 4, no. 1, pp. 67–80. https://doi.org/10.2478/s13533-011-0062-y