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| Succession of ecological environment in the last 50 years in Minqin Oasis of Gansu province and its comprehensive controlling countermeasures |
| Xu Xianying1,2,Ding Guodong1,Gao Zhihai2,Yang Zihui2 |
| 1.College of Soil and Water Conservation,Beijing Forestry University,100083, Beijing;2.Gansu Desert Control Institute,733000,Wuwei,Gansu: China |
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Abstract Under the dramatic influence of artificial factors on water,land and vegetation resources during the recent half a century,a series of great changes in eco-environment have taken place in Minqin oasis of Gansu province on such facets as the reduction of surface runoff amounts from 4.5×108m3 in 1950s to 0.89×108?m3 in 1990s in the lower reaches of Shiyang river,groundwater overexploitation causing decrease of groundwater level from average 1.52m in 1950s to 5?m in 1980s and 16.4m in 2002,increase of groundwater mineralization,degradation of natural and artifical vegetation,reduction of species diversity and succession of vegetation from hygrophilous vegetation series to xerophilous vegetation series,and the enlarge of land salinization area,serious land desertification,etc.Variation process of water resources and current situations are analyzed,as well as the irrational water utilization causing a series of ecological environment variation.Based on this analysis,some countermeasures to resources sustainable utilization and ecological protection were put forth in Minqin oasis for the purpose of harmonious development of ecology,society and economy.Tightening up the management of water resources through administration,economic and law means,applying water-saving irrigation methods so as to set up water-saving agriculture system,increasing the surface water amount from outer range for eco-environmental water demand,moving out a part of farmers to implement the harmonious development of mankind and nature,controlling the desertification land and reclaiming saline soil through the biological and mechanical methods are the main controlling measures to improve this situation.
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Received: 16 November 2004
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