Eco-Environmental Water Demand of the Rivers in the Northwest China

As a crucial ecological barrier region as well as the ecological fragile region,the rivers in the northwest China faced ecological water taken-up and serious eco-environment deterioration.Based on a comprehensive analysis,the general goal of eco-environment protection is purposed,i.e.to maintain the river ecosystem health and reasonable ground water table and form a virtuous circle of water ecosystem.Meanwhile,this goal is making for the harmonious development of economy and society,which depending on analyzing water resources conditions of rivers and making feasible,reasonable and limited objectives.To analyze eco-environmental water demand of rivers in the northwest China,water using for ecological vegetations along the river banks,water losing for evaporation and seepage,and water maintaining terminal lake should be considered.By calculation,the eco-environmental water demand is 79.818 billion m3,which takes up 63.17% of the surface water resources.The eco-environmental water demand varies greatly in different rivers.