小流域水文及土壤侵蚀过程模拟方法研究

Dynamic Simulation Method for Catchment Hydrologic and Soil Erosion Processes

流域土壤侵蚀动态模拟,需要采用合适的方法对坡面—沟道耦合问题及初始和边界条件进行正确的处理。将流域划分为坡面侵蚀与沟道侵蚀,采用时间空间耦合处理方法,实现了小流域坡—沟侵蚀过程中水流与泥沙输送的面—线耦合及沟道间的线—线连接。给出了模拟流域土壤侵蚀过程的控制微分方程、初始条件、边界条件及坡面向沟道汇水输沙的动态模拟处理方法。得到了较为符合实际的流域土壤侵蚀动态模拟模型。模拟结果与室内实验测量结果的比较表明,模拟精度达到80%以上,说明了动态模拟方法的可行性。

Dynamic modeling of hydrologic and soil erosion processes in catchment needs appropriate simulation methods to handle the water and sediment transfer on hillslope and in channel,as well as the initial and boundary conditions.Soil erosion in watershed,as a spatially and temporally coupled process,is divided into soil erosion in channels and soil erosion on hillslope.Soil erosion in watershed is partitioned into a surface-line system to deal with the hillslope-channel relation and a line-line connection for soil erosion in channel.The governing differential equation with initial and boundary conditions was outlined for watershed erosion modeling.The comparison of laboratory experimental results with model outputs indicates that the simulation accuracy is above 80%,which demonstrates the feasibility of the method.The simulation method presented in this study may supply a basis and reference for the simulation of soil erosion in watershed.