干旱区生态环境知识资源中心

In the paper, the author takes the Yan ' an city as a case, which is the representative areas of the northwest arid and sandy areas, in China, analyses the comprehensive effects on regional water resources, which caused by the changes of precipitation, the structure of social water use and soil and water conservation. On lie basis of these, the water resources in Yan' an city is rationally allocated, as the results are shown in this article. The author builds the rational water resources allocation model for Yan' an city, also, the author analyses the effects on the results of allocation, which front the change of climate, water and soil conservation arid the structure of social water use. rhe effects analysis includes the qualitative analysis and quanlificalional calculation. We find that the trend of precipitation is descending, but it ' s difficult to quantify the effect from the change of the global climate and the alternation between the flood and dry period. Art under the evolutional scenario of ecosystem, the flow in the river will be fluctuated less acutely, became evenly, it does good to utility water resources efficiently. The downstream water allocation is strongly influenced by the ways Of human get and use water on the upstream, because the drainage of upstream will pollute the water flow to downstream. At last, the author puts forward some proposals for rational water resources allocation, and discusses the issues for the future water resources allocation.