Analysis of sil erosion and fractional vegetation cover change in the Three Gorges Reservoir Area

Based on the Google Earth Engine (GEE) platform, the annual maximum NDVI images of the Three Gorges Reservoir Area were synthesized at 30 m resolution using Landsat data from 1987 to 2019, and the annual maximum fractional vegetation cover (FVC) of the Three Gorges Reservoir Area was calculated based on the image dichotomy method to analyze the spatial and temporal dynamics of FVC．Based on the GEE platform, the revised universal soil loss equation (RUSLE) was used to estimate the soil erosion (T) in the Three Gorges Reservoir Area in 2000 and 2010．The results showed that (1) the FVC in the Three Gorges Reservoir Area continued to improve from 1987 to 2019, and the area of the FVC increase area accounted for 75.35%, including a significantly increased area of 39.26%．(2) The soil erosion modulus (A) in the Three Gorges Reservoir Area was 25.51 \mathrmt\cdot \mathrmh\mathrmm^-2\cdot \mathrma^-1 in 2010, a decrease of 28.22% compared with 2000, and the intensity of soil erosion decreased significantly; the erosion area was 1.91\times 10^4\;\mathrmk\mathrmm^2 in 2010, a decrease of 27.38% compared with 2000．Soil erosion in the area with slope >15° exceeds 86% of the soil erosion in the whole area, soil erosion in the area with slope >25° exceeds 60% of the soil erosion in the whole area, soil erosion in the area with elevation 0-500 m exceeds 48% of the soil erosion in the whole area, and soil erosion in the area <1500 m is close to 70% of the soil erosion in the whole area, which is the key area for erosion control in the Three Gorges Reservoir Area．It is the key management area of soil erosion in the Three Gorges Reservoir Area．(3) From 1987 to 2015, rainfall slightly decreased and temperature increased, especially with the combined effect of human activities such as afforestation, which increased FVC and reduced soil erosion in the Three Gorges Reservoir Area．