The Spatial Distribution Relations between Erosion Gully and Terrain Factors in the South of Typical Black Soil Zone in Northeast China

With support of GIS and RS technology,combined with topography data and field survey,using SPOT-5 high-resolution remote sensing images,the article we extracted the quantity and density of erosion gully and devour cultivated land area by using GIS analysis functions in Jiutai,Jilin Province,discussed the relations between erosion ditch spatial distributions and the slope,aspect and slope shape of the study area,and analyzed the spatial distribution regularities of gully in different combinations of topographic features.Through studies,this article pointed out that when the slope increased the density of ditch increased first,then decrease.When the slope was greater than 5°,slope was not the main factors of erosion gully development.On different slope aspects,the soil erosion on the sunny slope was greater than the shady side,and there was a higher ditch density on windward slope than leeward slope.For different slope-shaped concave slopes most vulnerable to the occurrence of erosion ditch,followed by convex slope,straight slope was the most difficult in the occurrence of the erosion gully.Considered the combination of different terrain factors,the difference of the density of erosion was more obvious.On sunny slope,gully erosion occurred on convex slopes more easily than on straight slopes and concave slope.On shady slope,gully erosion most easily occurred on concave slope.Because different terrain factor combinations have different erosion densities,and thus in its governance should take different ways based on different conditions.