Digital watershed model for the Yellow River:construction and application

The digital watershed model for Yellow River is the main part of the "Digital Yellow River" Project.The digital watershed model of Yellow River is developed based on the hillslope unit,under the former constructed framework,which consists of six layers:the canopy storage,the snow storage,the surface storage,the top-soil storage,the middle-soil storage and the deep-soil storage.Three kinds of runoff are considered from the ground surface to middle soil:the overland flow for fast runoff,the interflow from the top soil and that from the middle one for slow runoff.The fast runoff is the response to the current precipitation,and the slow runoff reflects the influence of former precipitation,which is very important for rain-runoff simulation in the Yellow River basin.In addition,a soil-erosion formulation is proposed for the sediment yield simulation.The suggest model is applied in three cases:the computation of the water resources in the Yellow River basin,the rain-runoff simulation in Xiaolangdi-Huayuankou area,the soil-erosion simulation in the sandy and grit area in the Loess Plateau.The wellfitted results indicate that the model would have a good prospect of application in the future.