Research on the relationship between soil erosion and landscape pattern in Wuyuer river basin based on GIS

摘要

In recent years, soil erosion has been an increasing concern in the Black Soil Area of Northeast China because of its harm to the marketable grain basis in China. Taken Wuyuer river basin in Black Soil Area of Northeast China as study area, Using GIS, RS and USLE, by choosing the reasonable calculating methods to get each factor in the USLE, we evaluated the soil erosion of this basin in 2005a. Otherwise, chosen the 48 subbasin as basic analysis units, with the spatial analysis ability of GIS and FRAGSTAT software, it get the soil erosion modulus and corresponding landscape pattern metrics in each subbasin. Base on these data, the relationship between soil erosion and landscape pattern was analyzed and the result can provide suggestion for landuse planning and soil erosion control. It shows that middle and upper reaches of Wuyuer river basin is the main erosion region, and its mean soil erosion modulus is 258.85t/(km~2·a), which is higher than the tolerable soil loss rate in Black Soil Area of Northeast China. This region needs erosion control urgently. Correlation analysis shows a positive correlation between percentage of landscape(PLAND) of cropland, grassland, Perimeter-Area Fractal Dimension (PAFRAC), Shannon's Diversity Index (SHDI) and soil erosion modulus; Percentage of landscape(PLAND)of forest land as well as Contagion Index(CONTAG) show negative correlation with erosion modulus. With further analysis, it concludes that regulating the landscape pattern in cropland, grassland and forestland reasonably is very important for the soil erosion control and management.