There are 7.6 million hectares of irrigation development along the rivers Syr Darya and Amu Darya in Central Asia. Approximately one-half of this was developed since 1960. As a result, the volume of water reaching the land-locked Aral Sea has reduced dramatically, so that in only 30 years the level of the Aral Sea has fallen by 15 metres, the volume has decreased by 70%, and the salinity has increased so much that the once-productive fishery is now dead. The level of the Sea continues to drop at a rate of 0.3 m per year. Irrigation is estimated to consume 98 km3 of water per year (Bos 1995) or an average application rate of 1.24 m. Subsurface drainage has been installed in a large portion of the Aral Sea irrigation area but with widely spaced tubes, generally 800 m apart, installed at depths of 2.5 to 3.5 m.
Weitere Kapitel dieses Buchs durch Wischen aufrufen
- The Contribution of Horizontal Subsurface Drainage to Solving the Aral Sea Economic and Environmental Problem
David B. Chalcroft
- Springer Netherlands
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