In order to make distributed simulation for the impact of surface water storage factor on the ability of actual water supply in the upper reaches of Xinan river,the paper took the precipitation,potential evaportranspiration,characteristic parameter of underlying surface and combined water consumption to simulate the actual amount of water and its economic value in the upper reaches of Xinan river watershed in 2010. The results showed that actual water supply to downstream is 71. 1 × 108m3 and the total econ...