Estimation model and application of the amount of eco-water demand: a case study on Keriya river basin
流域尺度生态需水的估算模型与应用——以克里雅河流域为例

Eco-water demand is a focus of attention in ecological and water science research at present. Under the macroscopical background of implementing the west development strategy, pursuing the ecologi cal project of converting farmland into forest and grassland and realizing regional sustainable development of China, water and land resources distribution, esp ecially the deficiency of water resources has restrained the development and utilization of western region's resources and become an urgent problem awaiting sol ution. Just because of this, the assessment of the scale and intensity of basin ecosystem eco-water demand is of positive and realistic significance. This paper, with western arid climate and hungriness environment as the research object , through analyzing the structure characteristics of different ecosystem's eco-water demand, synthetically estimates the scale of eco-water demand and analyzes the question of equilibrium of supply and demand of eco-water requirement in terms of maintaining the basic amount of ecological base flow of the fundamental eco-environmental function of the drainage channels, keeping basin channels' moisture balance for sediment and salt discharge and maintaining the basin's ecol ogical balance by minimizing water consumed for vegetation evapotranspiration.The research result indicates that the total eco-water demand in the whole basin is about 6.93×109m3/a, accounting for 50.5% of the total amount of the basin's recent available surface water resources, groundwater mining and many years spring average foot-path flow.The development and utilization degree of this basin surface water has already exceeded rational threshold value. The average minimum eco-water demand per ha of vegetation is 413.9 m3/a.Of the eco-water consumed for different types of vegetation, marshland, meadow and forest land separately account for 47.6%, 43.4% and 9.0% of the total water requirement. Marshland and meadow are the principal eco-water consumers. Resear chresults have important reference value to make development and utilization plan of water and land resources, for local government, guarantee the benign cycle of the water resources, realize the sustainable utilization of the water resources, restore and rehabilitate the eco-environment.