关键词: 土壤侵蚀, 植被, LMDI, RUSLE, 定量分析, 三江源地区

Abstract: In the purpose of quantitatively evaluating the influence of vegetation change on soil erosion modulus, we conducted pixel statistical calculation and adopted the RUSLE model to explore the changes of vegetation coverage and soil erosion modulus in three periods from 2000 to 2015. Moreover, we employed the logarithmic mean Divisia index (LMDI) decomposition model was used to quantitatively analyze the contribution of vegetation to the changes of soil erosion modulus from the pixel scale. Results showed that the vegetation coverage in the Three-River Headwaters Region displayed an overall increasing trend, yet still with some differences in different periods. In general, the soil erosion modulus had been decreasing, and the spatial distribution characteristics between the changes of erosion modulus and the changes of vegetation coverage in each period were not identical, mainly because soil erosion change was caused by multiple factors. Vegetation had a positive effect on changes of soil erosion, and the contribution values ranged between -100 t·hm^-2·a^-1 and 100 t·hm^-2·a^-1. The spatial distribution characteristics of the contribution values were consistent with the changes of vegetation coverage. The LMDI model is a good method to quantitatively analyze the effects of vegetation on changes of soil erosion modulus from the pixel scale and provides new ideas for soil erosion management. The ecological conservation and restoration project in the Three-River Headwaters Nature Reserve has achieved benefits, and environmental projects should be strengthened.

Key words: soil erosion, vegetation, LMDI, RUSLE, quantitative analysis, Three-River headwater region