Characterization of Spatial and Temporal Distribution of Soil Erosion on the Loess Plateau of Inner Mongolia and Analysis of Its Influencing Factors

Based on soil erosion data, the changing status of soil erosion was studied, combining multi-source data from nature, socio-economics and geographic location, applying a random forest regression model to rank the importance of the selected 10 influencing factors, and comparing the predicted and actual values of soil erosion in different years. The results indicated that the average soil erosion modulus on the Loess Plateau of Inner Mongolia changed from 1221.96 t/(km²·a) to 155.97 t/(km²·a) from 2001 to 2020, mainly with the largest proportion of slight and light erosion, and the area of slight erosion increased and the area of light, moderate and strong erosion decreased during 20 years. According to the model results, there are 5 factors that significantly affect the occurrence of soil erosion in the Loess Plateau area of Inner Mongolia. Among these factors, slope is the most significant factor that affects the occurrence of soil erosion. The other significant factors are ranked in order of importance: nearest distance to settlement > nearest distance to road > NDVI > average annual precipitation; R² value of the model was 0.89, indicating a good fit and applicability to predicting soil erosion in the Loess Plateau region of Inner Mongolia. A risk map of soil erosion occurrence revealed that areas with high probability of soil erosion were mainly concentrated in the northern part of the Inner Mongolia Loess Plateau, Hohhot and Baotou in the northeast, and Alxa Left Banner in the west, which were more significantly affected by the combined effect of human development activities and natural factors.