基于DEM通用土壤流失方程地形因子的算法设计与优化

The Algorithm Design and Optimization for Topographic Factors of Universal Soil Loss Equation Based on DEM

论述了通用土壤流失方程在区域尺度应用时,基于数字高程模型计算其地形因子的算法及其流程,并在ArcGIS的GRID平台上开发实现。实践证明,采用最大坡降坡度法和累积坡长法求取坡度和坡长,进而计算通用土壤流失方程地形因子的算法合理可信。通过水系数据的叠加优化,一方面提高了程序的计算效率,同时也减少了不合理累积坡长值出现的机率。

The author discusses the algorithm and the flowchart of topographic factors based on digital elevation model （DEM） when universal soil loss equation is used on regional scale. The program is developed on GRID model of ArcGIS. By practice, it is recognized that the algorithm of topographic factors computing slope degrees and lengths through maximum downhill slope and cumulative slope length method is reasonable and reliable. Via the overlay optimization of water system data, the efficiency is improved, at the same time, the probability of unreasonable cumulative slope length value is decreased.