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Mirzakhayot Ibrakhimov Christopher Martius J.P.A. Lamers Bernhard Tischbein 《Agricultural Water Management》2011,101(1):52-61
Salinization of irrigated agricultural land threatens ecological sustainability and livelihoods of people. Salinization is especially severe in the dry lowlands world-wide and in Central Asia where large amounts of salts accumulated in the soil profile, originating from shallow saline groundwater (GW). Analysis of the unique dataset of 2000 monitoring wells of GW table and salinity in lowland Khorezm region of Uzbekistan over the period of 1990 till 2006 showed shallow GW levels of 1.1-1.4 m (±0.48-0.66 m) at start of leaching periods and 0.9-1.4 (±0.43-0.63 m) in July during the annual growing seasons. While leaching efficiency is decreased, shallow GW in July is far above the optimum levels of 1.4-1.5 m. The effects of topography, soil texture, and irrigation and drainage networks were found to favor shallow GW forced by excessive water diversion. The drainage network, which is seen by many specialists as underdeveloped and its improvement necessary to arrest unacceptable GW levels, is being used under its full capacity. The solution to alleviate land degradation is not only an improved drainage, but better controlled and more flexible water management. 相似文献
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M. Ibrakhimov A. Khamzina I. Forkutsa G. Paluasheva J. P. A. Lamers B. Tischbein P. L. G. Vlek C. Martius 《Irrigation and Drainage Systems》2007,21(3-4):219-236
Groundwater (GW) management is an essential element in irrigated agriculture. This paper analyzes the temporal dynamics of
GW table and salinity in Khorezm, a region of Uzbekistan which is situated on the lower Amu Darya River in the Aral Sea Basin
and suffering from severe soil salinization. We furthermore identify the critical areas for potential soil salinization by
examining GW table and salinity measured during 1990–2000 in 1,972 wells, covering the entire region. Additionally, case studies
were performed to assess the contribution of the GW to the soil salinization on a field scale. Over the entire area, GW was
only moderately saline averaging 1.75 ± 0.99 g l−1 However, GW levels were generally very shallow averaging 148 ± 57 cm below the ground surface and thus likely to prompt secondary
soil salinization. Three case studies where GW table, soil and GW salinity were closely monitored at the field scale, suggested
that the elevated GW levels forced soil salinization by annually adding 3.5–14 t ha−1 of salts depending on the position and salinity of the GW table. Maps interpolated from the regional dataset revealed that
GW was significantly shallower and more saline in the western and southern parts of Khorezm despite the presence of a drainage
network which is rather uniformly distributed throughout the region. The results of the current study will assist the development
of an improved drainage management in Khorezm. 相似文献
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