Study On Criterions And Control Techniques Of River Eco-water Usage In Semi-arid And Semi-humid Area

This paper discussed the river eco-water usage problems in semi-arid and semi-humid areas based on the achievements of the project of eco-water use in Chinese difference regions which is a important project in the tenth five plan.The theory system has been set up based on the effect of ecology system during the water cycle, and started with basis, application, and decision levels. The concepts of "ecological standard river" and "eco-hydrological seasons" were put forward. The eco-water usages in large rivers have been studied based on those results, so this paper studied it in small rivers as a further research and made the following works based on those theories:â‘  Analyzing river characters of physiognomy, hydrology andtheir effect on ecology system.â‘¡ Analyzing characters of river ecological water requirementin small watershed of the semi-arid and semi-humid area underthe frame of tenth five plan project's theory system.â‘¢ Selecting the rivers in Yan-An region and BiLiuhe river asobjects to calculate their standards of eco-water usage.As a result, the conclusions from these works were applied on...