Research on Ecological Rehabilitation and Water Demand in Northwest China

With the development of society and economy in northwest China,the exorbitant exploitation and utilization to resources causes local ecology and environment system destroyed badly,which becomes the most restriction factor of sustainable development.Therefore,researches on ecological rehabilitation and water demand in northwest China have important significance to protect local ecological system.Based on the differences of the landforms,hydrology and meteorolog y conditions and characteristic of ecological system structure on the space scal e,the northwestern region of China is divided into 5 first-degree subregions and 16 second-degree subregions above all.According to each ecological subregion,the goals and measures of ecological rehabilitation are put forward,considered synthetically the local nature condition and current ecological and environmental problems.The calculation method of ecological water demand is introduced,and the quantity of water demand in each subregion is got by the method.The result shows that total ecological water demand quantity of northwest China is 2.88× 10~(10) m~3,and the water demand quantity of Tarim Basin subregion is the biggest in the subregions.In the end,the conclusion is that the ecological and environmental retrogression is a ubiquitous problem,the ecological rehabilitation is quite essential and urgent,rational allocation to water resources is the pivotal link of ecological rehabilitation,the choice of vegetation seed must fit the actual situation of each division and ecological water demand will be ensure to be sufficient as much as possible