Erosion and Sediment Yield Model of Big and Middle Scale Watershed in Loess Plateau Considering Differentiation Between Upper and Lower of the Shoulder Line of Valleys
Erosion and sediment yield between the upper and lower of valleys shoulder line in Loess Plateau are very different.Uncertainty exists while applying mechanism model in big and middle scale watershed.Under this circumstance,automatic extraction technology of the shoulder line of valleys with hydrologically correct digital elevation model data was introduced to divide topography units into inter-gully and gully bank.Through improving the algorithm of slope length factor and re-construction of vMley slope erosion model structure,it was put forward that erosion in inter-gully unit and gully bank unit could be calculated respectively by universal soil loss equation and reformed slope-gully erosion statistic model,which were further integrated with sediment delivery distributed model to construct the model system for simulating the distribution of erosion and sediment yield of watershed.The simulation result in the upper reaches of Beiluo River shows that the model system can well simulate erosion and sediment yield of watershed in the scales of annual average and inter-annual.This provided a credible proof on that the model system was useful in benefits evaluating,prevention and control planning of water and soil conservation for large and middle watersheds of Loess Plateau.
erosion and sediment yield modeluniversal soil loss equationgully erosionsediment delivery ratioLoess Plateaubig and middle scale watershed