水蚀模型USLE与WEPP在紫色土水蚀预测中的应用对比研究

Application and comparison of the erosion model USLE and WEPP in predicting erosion of purple soil

该文分别确定了USLE与WEPP模型的参数指标,通过实测遂宁组紫色土的单次降雨产沙量,对降雨产沙实测值与模型预测值进行比较分析,结果表明:在20°休闲小区模拟预测WEPP模型预测效果多数情况下优于USLE模型;通过多因子贡献分析发现,降雨量因子对产沙量的影响最大,其对休闲区和布设措施小区产沙量的贡献率分别达到了48.0%和64.1%。根据统计学中累积贡献率大于80%确定公共因子的原则,确定降雨量与降雨历时为遂宁组紫色土地区侵蚀产沙量的公共因子。

As the most complicate soil erosion prediction model, WEPP model has got extensive research and application in our country. The paper ascertains the USLE and WEPP model parameters respectively and compares the measured value and predicted value, through observing the sediment yield under single rainfall in Suining group purple soil. Results showed: the most of predicted values by using WEPP model are more accurate than those by using USLE model in 20 degree fallow plot. Rainfall factor is the most important influence factors to sediment yield, no matter in fallow or measured plot, through analyzing the contributed rate of many factors. The contributed rate to fallow and measured plot produced by rainfall is 48.0% and 64.1% respectively. According to the principle that accumulating contribution rate is more than 80% in statistics, the rainfall and rainfall duration is the public factor for erosion sediment yield in Suining group purple soil.