WEPP水蚀预报流域模型

Water Erosion Prodiction Project(WEPP) Model for Watershed Scale

ＷＥＰＰ是“新一代水蚀预报技术”开发的计算机土壤侵蚀预报模型，可用于水土保持规划、环境规划及评价。ＷＥＰＰ是以随机天气生成模型、入渗理论、水文学、土壤物理、作物科学、水力学和侵蚀力学为基础开发的，它在坡面的应用及流域版的基本功能使它比现有侵蚀预报模型有明显优越性，主要包括：（１）估算土壤侵蚀时空分布即全坡面或坡面任一点的净土壤流失量及其随时间的变化。（２）ＷＥＰＰ模型是过程模型，可应用于更广泛的条件下。主要介绍了ＷＥＰＰ模型流域版的基本概况和用美国６个不同地方１５个小流域实测资料的检验结果。

The Water Erosion Prodiction Project(WEPP) watershed scale model was developed by the USDA for soil erosion assessment and conservation planning.Serveral sensitivity analyses and evaluation studies have been conducted for the WEPP hillslope version, but few efforts have been made to evaluate the accuracy of WEPP watershed model predictions by comparing predicted results to measured data.The purpose of this study was to give a brief introduction of WEPP watershed model and to evaluate the WEPP watershed model applicability and prediction accuracy for small watersheds under different climates ,topographies ,soils,and managements .Data from 15 watersheds of 6 locations in the United States were compared to runoff and sediment yield estimates using WEPP95.The result shows that the WEPP predicted reasonable average annual and event runoff and sediment yield with default parameter estimation procedures for most of the sites and individual watersheds.Model efficiencies for storm by storm runoff and sediment yield were quite reasonable for general conditions.The distributions of measured and predicted events were similar.This study also pointed out the potential areas for model improvement ,including better and more specific silage routines,in addition of a weed component to the plant growth and management model,and better linkage of the sediment from contoured hillslopes to the watershed channel system.