黄土丘陵沟壑区典型小流域侵蚀产沙过程模型

PROCESS-BASED SOIL EROSION AND SEDIMENT YIEID MODEL IN A SMALL BASIN IN THE HILLY LOESS REGION

在分析现存土壤侵蚀产沙模型基础上，依据大量小流域野外试验小区观测与模拟降雨试验资料，建立了一个适用于黄土丘陵沟壑区小流域预测侵蚀产沙量的侵蚀产沙过程模型。由于黄土丘陵沟壑区小流域的复杂地形和侵蚀产沙的垂直分带规律，土壤侵蚀产沙的空间变化要比现有模型复杂得多，因此，本模型由三个子模型组成：坡面子模型、沟坡子模型、沟道子模型，它可以计算小流域每场暴雨的径流量与侵蚀产沙量。本文较为详细地描述了模型中计算所用的方程和子模型运算框图。

The loess Plateau region, where the study area is located,is one of the most severely eroded regions of China. In reviewing the existing models,we have developed a process-based soil erosion and sediment yield model to predict small basin sediment production in the hilly loess region.In the view of the complex topographical conditions. a wide range of processes and subprocesses of erosion are active, and the associations produce patterns of down slope changes in soil loss which are considerably more variable than the systematic changes generally reconginzed in existing models. This model is divided into three submodels: the hillslope submodel,the valley slope submodel, and the channel submodel.Spatial units considered in this model are parcels of land with general homogeneity in characteristics, i. e.slope zones. For the temporal scale, the model is designed to estimate per storm responses in runoff and soil loss. The specific equations and the algorithm flow chart of three submodels are given seperately in this paper.