Risk Evaluation of Water Shortage in Source Area of Middle Route Project for South-to-North Water Transfer in China

Water diversion causes changes in the downstream flow regime, which may intensify the crisis of water shortage. The effect of the diversion on water shortage depends on the volumes of water transferred and water demand of source area, the upstream inflow and the way the reservoir is operated. This paper reports the findings of a study to assess the impact of water diversion from Danjiangkou reservoir on middle and lower Hanjiang River, part of the source area of South-to-North Water Transfer Project, China. The risk evaluation model consists of four parts, including inflow generation, water demand, simulation, and performance evaluation. Thomas–Fiering model and Mont-Carlo method are utilized to simulate monthly reservoir inflow data and a 12-dimensional random vector is used to describe the 12-month water demand in middle and lower Hanjiang River. A reservoir simulation model is established for optimum operation of Danjiangkou reservoir. Several scenarios including different water diversion scales are run by the risk evaluation model, whose outputs provide valuable information for decision making.