Analysis of Spatial and Temporal Changes and Driving Factors of Soil Erosion in Longchuan River Basin in Recent 20 Years

Abstract

[Objective] The objective is to explore the spatial and temporal changes of soil erosion and its main controlling factors in the Longchuan River Basin, as well as to understand mastering the local soil and water, which is conducive to building an ecological barrier in the upper reaches of the Yangtze River. [Methods] The temporal and spatial variation characteristics of soil erosion in the Longchuan River Basin during 2000 to 2020 were studied using the revised universal soil loss equation (RUSLE) combined with GIS and RS technology. Additionally, the optimal parameters-based geographical detector (OPGD) model was used to quantify the influence and interaction of driving factors on the temporal and spatial dynamic changes of soil erosion in the Longchuan River Basin. [Results] (1) Soil erosion in the Longchuan River Basin was mainly slight and moderate erosion. In 2000, the proportion of slight and moderate erosion was 49.17%. In 2010, the total proportion was 50.29%; In 2020, the total proportion is 59.29%. There was little change in soil erosion from 2000 to 2010, but from 2010 to 2020, a total of 9.01% of areas experiencing soil erosion transitioned from moderate to slight or mild levels. (2) The results of the OPGD showed that the land use type had the strongest explanatory power for the temporal and spatial dynamic changes of soil erosion in the study area, with a q value was 0.18. The interaction between land use type and slope had the strongest explanatory power for soil erosion in Longchuan River Basin, with a q value reached 0.45. [Conclusion] Soil erosion in the Longchuan River Basin is mainly slight and mild, with an overall improving trend, but there are still areas with strong soil erosion. Land use type has the strongest impact on soil erosion in the basin, with woodlands and meadows being the most important types covering 67.02% of the total area in the study area. In the future, we should focus on regional changes in vegetation coverage, continue to promote ecological protection policies, and be alert to the risk of soil erosion in complex terrain areas.

Keywords

• soil erosion
• rusle model
• opgd model
• vegetation coverage
• longchuan river basin