蒲河流域退耕前后降水和植被对土壤侵蚀变化的影响

为了定量评价退耕还林还草前后蒲河流域土壤侵蚀变化特征及降水和植被对土壤侵蚀的影响，运用修正后的通用土壤流失方程(RUSLE模型)探讨1990—2019年流域土壤侵蚀变化，结合LMDI模型评估了1990—2000年、2000—2010年、2010—2019年3个时间段植被和降水对流域土壤侵蚀变化的影响。结果表明：30年来，流域侵蚀强度以微度和轻度侵蚀为主，而中度及以上等级的土壤侵蚀面积有逐渐减小的趋势；流域侵蚀情况总体持续向好，植被覆盖度与降雨侵蚀力相互作用驱动了研究区土壤侵蚀的动态发展；2000年以前，降水是影响土壤侵蚀变化的主导因素，随着退耕还林还草工程的实施，植被作用逐渐凸显。蒲河流域的退耕还林还草成效显著，是流域侵蚀防治的有效措施，应在侵蚀较强的流域中上游地区继续加强植被恢复措施。

Influence of Precipitation and Vegetation on Erosion Change Before and After Grain for Green Project in Puhe River Basin

In order to quantitatively evaluate the change characteristics of soil erosion and the effects of precipitation and vegetation on soil erosion in Puhe River Basin before and after Grain for Green Project, we used the revised universal soil loss equation(RUSLE) model to assess soil erosion in Puhe River Basin and analyzed its dynamic changes from 1990 to 2019. Combined with LMDI model, we studied the effects of vegetation and precipitation on soil erosion in this basin from 1990 to 2000, 2000 to 2010 and 2010 to 2019 at the pixel scale. The results show that: over the past 30 years, the erosion intensity of the basin was mainly micro and mild erosion, while the soil erosion area of medium and above levels tended to decrease gradually; the overall erosion situation of the basin continued to improve, the interaction between vegetation coverage and rainfall erosivity drove the dynamic development of soil erosion in the study area; before 2000, rainfall was the dominant factor affecting the change of soil erosion; with the implementation of the Grain for Green Project, the role of vegetation became more and more prominent. The research shows that the Grain for Green Project in Puhe River Basin has achieved remarkable results, which is an effective measure for erosion control and the vegetation restoration project should continue to be strengthened in the middle and upper reaches of this basin.