Relationship between gully erosion and agricultural landscape pattern in the typical black soil region of Northeast China

Abstract

The black soil region of Northeast China is an important grain producing area that faces a serious erosion problem. We used SPOT5 remote sensing imagery from 2008 to establish the gully distribution in a typical black soil region located in the Wuyuer and Nemoer River basin, and Landsat Thematic Mapper imagery to designate landscape patterns. Ninety-three sub-basins were determined based on digital elevation model data using a hydrological analysis module for which landscape pattern metrics and gully density were obtained using FRAGSTATS software and the Geographic Information System (GIS) spatial analysis function, respectively. The results show a gully density of 4,219.2 m2/km2 with 10,149.5 ha of eroded dry land and 25,261.2 ha of destroyed dry land. Correlation analysis between gully density and the landscape percentage of dry land and forest, perimeter-area fractal dimension, contagion index, and Shannon’s diversity index indicate that regulation of the proportion of forest, dry land, and grass, and reasonable optimization of landscape arrangement is very important for soil erosion management and control. Additionally, the findings indicate that landscape differences between each sub-basin are not the principal reason for differences in gully erosion. Further research on gully formation should integrate the effect of natural forces and human activities.