Abstract: Slope body is the basic unit of natural terrain entity. It is beneficial for regional landform analysis and planning to use comprehensive slope factor analysis and excavation of terrain implied information. Because of the current defect that the slope width factor has not been considered in the slope comprehensive expression factor(LS), a new slope fusion factor(LSW) is acquired by integrating the slope length (L), slope (S) and slope width (W) with the normalized geometric operation method. Using DEM by intercepting a local area of a small watershed in the Loess Plateau as a typical study area, four patterns L×S×W, L+S+W, LS×W and LS+W are adopted for the fusion experiment based on the extraction of L, S, W and LS. The experimental results show that the L+S+W fusion pattern has the lowest mean value 0.2344 in the LSW factor variance matrix, effectively balances the contribution of each single terrain factor in LSW to the fusion slope factor LSW, and the L+S+W fusion pattern is demonstrated to be optimal by information entropy calculation.

Key words: digital terrain analysis, gird DEM, slope body factor, slope length, slope, slope width