中文摘要：

针对典型丘陵区土地整理项目,利用坡面土壤侵蚀WEPP机理模型,模拟不同坡地梯田改造后土壤流失量和产沙量的长期变化,及土地利用和耕作措施的影响。结果表明,随着坡度增加,坡地的梯田整理对于减少土壤流失量的作用减弱,但对于减少总产沙量作用增加。土地利用方式影响土壤流失量和产沙量,由高到低为常规耕作的农田、草地和灌丛。对于耕作措施来说,小麦玉米轮作条件下,免耕措施与传统的耕作措施相比,可以明显降低土壤流失量和产沙量。土壤流失量受降雨的影响制约,休闲地日降雨量超过12mm时产生土壤流失,而农田日降雨量超过20mm时才产生土壤流失,降雨量越大,梯田减少土壤流失的效应越明显。长期模拟结果表明,土壤流失的年际变化受降雨量变化主导,土壤流失量变化趋势与降雨量变化一致。

英文摘要：

Focusing on land consolidation projects in a typical hilly region, WEPP model was used to simulate the long-term effects of the projects as well as soil conservation measures including different land uses and tillage system on soil erosion process. The results showed that with increasing the slope, the mitigation effect of land consolidation on soil loss decreased, while the effect on the mitigation of total sediment yield in- creased. Land use types affected the amount of soil loss and sediment yield, which decreased in the order of farmland, grass and shrub. For the local wheat-corn rotation system, no tillage system significantly de- creased the soil loss and sediment yield compared to conventional tillage system. Soil loss occurred in the fallow when rainfall was greater than 12 mm per day and in the farmland when rainfall was greater than 20 mm. After consolidation, the mitigation effect of terrace on soil loss increased with the increase of rainfall. Long- term simulation showed annual soil loss was dominated by the annual rainfall and the tendency of soil erosion was consistent with the rainfall dynamics.