Estimating Depositional Topography Factor On Hillslope

Deposition is an important part of the surface erosion process. There are a lot of research On the relationship between topography and soil erosion process has focused on the impact of soil erosion and sediment yield process, but ignore the sediment deposition. This paper is based on the soil erosion, hydraulics, sediment dynamics and other disciplines, Finally based on the5m’s DEM, analysis the effect of terrain on sediment deposition process through different algorithm to extract the deposition terrain index. The deposition terrain index can characterize the relationship between terrain and sedimentation. Through the statistical analysis and spatial distribution analysis we can get the following conclusion:(1) Deposition is an important part of the whole soil erosion process. According to this relationship, we put forward using depositional topography factor the amount index to characterize the relationship between the sedimentation and topography; This process have close relationship with terrain. And according to this relationship, We use a certain indicators which called depositional topography factor to characterize the relationship between the sedimentation and topography;(2)Based on the geomorphology and hydrology, Moore’s, Mitasova’s and Gruber’s those three algorithms both can express the relationship between the intensity of sedimentation and terrain. Comparison and analysis the three algorithms, all they can show deposition location and relative amounts, but the pattern of performance is different. The reasons need continue to study.(3) Slope、plan curvature and LS factor are most obvious with the Depositional topography factor. Deposition occurred in areas which Slope vary from steep to slight and LS factor vary from large to small.Depositional topography factor on the concave slope has great value.