Research on the Influencing Factors of Gully Erosion in the Black Soil Region of Northeast China

The unique environmental settings and increasing human activity in Northeast China have intensified gully erosion, threatening food security and sustainable development. However, systematic studies of environmental thresholds driving gully erosion remain scarce. This study analyzed erosion gullies across four typical regions of Northeast China using Google Earth imagery (2011 to 2021) and field survey data (2021) to investigate the (1) conditions under which gullies most frequently form and develop and (2) conditions conducive to gully stabilization. Results showed that, in semi-humid areas, gullies mainly developed on cultivated land with a gradient of 6–15°, though catchment area thresholds varied. In contrast, in the semi-arid mountain and hilly area, developing gullies grew fastest in forested areas with low vegetation coverage. Overall, while there were differences across the four regions, gullies were most likely to form on cultivated land, while stabilized gullies were concentrated in forested areas. These findings indicate that the conversion of cultivated land to forested land slows the development of erosional gullies. In addition, rainfall promotes the formation of new gullies and inhibits the growth of eroded gullies by reducing the effective drainage area. The results provide a theoretical basis for the prevention and control of gully erosion.