中文摘要：

通过人工模拟降雨，研究不同地形（不同坡度和坡长）条件下枣树坡地产流产沙规律，并采用WEPP模型对径流和产沙进行模拟。结果表明，当降雨强度一定时，水流的含沙量随着坡长的增加而增大，随着坡度（16°，21°，26°）的增加，在210时产流产沙过程始终保持最低，而产流时间则随着坡度的增加而提前；当降雨强度逐渐增大时，径流量与坡长呈线性关系，产流时间则随坡长的增加而推后，产沙量与坡长则呈指数关系。不同坡度条件下，降雨强度大于1．15mm／min时，产流和产沙量均明显增加。WEPP模型对产流量和产沙量模拟的有效性ME分别为0．796和0．585，说明模型模拟结果合理，且产流量的模拟精度要高于产沙量的模拟精度。

英文摘要：

The experiment of simulated rainfall was carried out on hillslope planted with Jujube in Yulin City in Northern Shaanxi with small rainfall and concentrated rainstorm. The process of runoff and sediment were observed from different terrains （different slope grades and lengths） and were simulated by using WEPP （Water Erosion Prediction Project） Model. The results showed that under a given condition of certain rainfall intensity, the yield of sediment increased with increasing of slope length and grade, under the slope grade of 21°, and the amount of runoff and sediment generation were relatively small compared with the slope grade of 16° and 26°, and the time of runoff generation got earlier with the increase of the slope grade. With the in- creasing of rainfall intensity, there was significant linear relationship between runoff and slope length and there was an exponential relationship between sediment and slope length. The runoff and sediment yield in- creased significantly when the rainfall intensity was more than 1.15 mm/min, and the time of runoff genera- tion got later with the increase of the slope length. The values of ME （Model Effectiveness） for simulating runoff and sediment yield with WEPP model were 0. 796 and 0. 585 respectively. As a result, the WEPP model could be used for simulating runoff yield and sediment derived from hillslope planted with Jujube in Northern Shaanxi and the simulation accuracy of runoff yield were higher than sediment.