Spatial-temporal variation analysis of soil erosion based on multi-source data—A case study of Susong County, Anhui Province

This paper analyzed spatial-temporal variation of soil erosion in Susong County from 2015 to 2019 and discussed the influencing factors of soil erosion based on geographic information system (GIS) and soil loss equation (RUSLE) model. The results showed that: ① The soil erosion modulus of the study area in 2015 was 612.53 t/(km²·a), and the total eroded area covers 1 339 078.87 t/a, which is distributed in the pattern of strong eroded northwest and weakly eroded middle and south. ② Soil erosion did not change significantly with slope, mostly concentrated in the 0~15° slope zone and dominated by slight, light and moderate erosion, with the largest eroded area in the eastern slope, followed by the western slope. ③ Among the different soil types, the largest eroded area is brown-red soil, followed by gray fluvo-aquic soil, in terms of land use types, the largest soil-eroded area was in cultivated land, followed by water area and forest land. ④ From 2015 to 2016, the total amount of erosion increased and the intensity of soil erosion kept improving with the moderate and above erosion accounting for a large proportion. After 2017, the total amount of soil erosion decreased and the areas of intense and extreme erosion gradually changed into those of moderate and light erosion. This study shows that precipitation, vegetation cover, topography and human activity disturbance together affect the soil erosion variation.