Comparative analysis of two distributed soil erosion and sediment yield models in Sichuan Basin, China

摘要

Based on data from two watershed outlets, and three runoff plots in the purple soil hilly areas of Sichuan Basin, two distributed soil erosion and sediment yield models were constructed. One is based on a grid with 20-m resolution in Hemingguan Watershed, with an area of 0.419 km~2, and the other is based on a land plot in Lizikou Watershed with an area of 19.63 km~2. Comparison of these two models shows that the simulation based on the high precision grid is more accurate. When the area of a watershed is larger than 10 km~2, the accuracy of the model will be increased if a high-resolution grid is adopted, whereas if the resolution of the grid is low, the grid will generalize too much information, such as different land-use patterns in the same grid. On the other hand, a distributed model based on a land plot can substantially reduce the computational complexity because the land-use means are uniform. The two models basically have the same structure, but the Hemingguan model is more accurate than the Lizikou model.