基于RUSLE、InVEST和USPED的土壤侵蚀量估算对比研究 ——以陕北延河流域为例

黄土高原是我国水土流失的重灾区，准确地估算土壤侵蚀量对于当地的退耕还林、水土保持以及土地管理等措施的实行具有重要的指导意义。本研究选取黄土高原延河流域为研究区，以2000年、2005年、2010年和2015年共4期的Landsat TM遥感影像及日降雨量、土地利用、数字高程模型和土壤属性等为源数据，比较RUSLE、InVEST和USPED三个模型对土壤侵蚀的估算在该研究区的适用性，并分析不同地形和植被条件下土壤侵蚀的分布及变化规律。研究发现：1）2000年后延河流域土壤侵蚀量先增加后减少，2005年后减少幅度逐渐增加，表明退耕还林工程效果显著；2）与实测产沙量数据相比，RUSLE模型估算的侵蚀量偏大，USPED模型和InVEST模型的误差相对较低，建议在延河流域使用InVEST和USPED模型计算土壤侵蚀；3）土壤侵蚀量随坡度的增加而增加，RUSLE模型增加幅度最大；4）当NDVI > 0时，土壤侵蚀量随NDVI的增加而减少，并且当NDVI在0 ~ 0.1时，土壤侵蚀量最大。

A comparative study of soil erosion estimation based on RUSLE, InVEST and USPED models: A case study of the Yanhe River Basin in Northern Shaanxi

The Loess Plateau suffers from severe soil erosion in China. The accurate estimation of soil erosion has important guiding significance for the implementation of local projects such as land management, water and soil conservation. In this study, we selected Yanhe River Basin as the study area, and four years Landsat TM remote sensing data (in 2000, 2005, 2010, and 2015), rainfall, land use, DEM and soil properties as the source data. We compare the RUSLE, InVEST and USPED models in the studied area. We analyze the prediction accuracy under different terrains and vegetation distributions. The results showed that (1) soil erosion in the Yanhe River Basin increased first and then decreased from 2000. The reduction gradually increased after 2005. It indicates that the project of Grain for Green had a significant effect; (2) compared with the sediment yield data, the amount of soil erosion predicted by the RUSLE model are relatively large, and the USPED and InVEST models are more accurate than RUSLE model. Therefore, the InVEST and USPED models are suggested to predict soil erosion in the Yanhe River Basin; (3) soil erosion increased with the increase of slope, and the RUSLE model increased the most; (4) when NDVI > 0, soil erosion decreased with the increase of NDVI; and when NDVI was between 0 and 0.1, soil erosion was the largest.