Gully status and relationship with landscape pattern in black soil area of Northeast China

The regulation of land use structure, improvement on quantity proportion of landscape constituent and optimization of the landscape patch spatial distribution are the important measures to control erosion. Taking Kedong county in typical black soil area of Northeast China as study area, using SPOT5 image as basic data source, gully distribution status and landscape pattern were obtained for the study area. Based on hydrology analysis module, 55 subbasins were extracted as basic analysis units, then gully density and landscape pattern metrics in each subbasin were gotten using GIS spatial function and FRAGSTAT software, respectively. By correlation analysis, the relationship between gully erosion and landscape pattern was analyzed. The results showed that the number of gully is 2?246. The shortest and longest gully was 19.7 m and 12?499.43 m, respectively. Gully density is 479.15 m/km2. The erosion area of cultivated land was 1?734.05 hm2 and the area of destroyed cultivated land was 8?067.5 hm2. The study area is a typical matrix-patch-corridor agriculture landscape and the high factitious dry land is the main reason to cause erosion . Single-factor correlation analysis between gully density and percentage of landscape (PLAND) of dry land, forest, Perimeter-Area Fractal Dimension (PAFRAC), Contagion Index (CONTAG), and Shannon’s Diversity Index (SHDI) showed that regulating the percents in dry land, grass and forest and optimizing the landscape configuration reasonably were very important for the soil erosion control and management. Multi-factor correlation analysis between gully density and landscape metrics showed that the difference of landscape pattern in subbasin was not the key reason that caused the difference of gully erosion, and therefore, research on gully formation need to integrate natural and human activities factors for further study. The research can provide suggestion for land use planning and soil erosion control in agriculture landscape.