论文部分内容阅读
地形(LS,slope length factor and slope steepness factor)因子是通用土壤流失方程和修正通用土壤流失方程USLE/RUSLE(universal soil loss equation,revised universal soil loss equation)应用到流域或区域尺度时较难提取的因子。基于坡面水文学和土壤侵蚀学,对流域地形因子的原理、方法、流程进行了讨论。考虑了三维坡面水流发散和汇聚、泥沙沉积、沟道截断等条件,基于GIS技术,提出了基于多流向的地形因子估算方法,设计了LS_TOOL工具。该方法与已有AML(ARC Macro Language)和C++方法计算的坡度坡长结果在空间分布、运行效率等方面进行对比,结果表明:采用多流向方法,计算合理,符合地形因子计算的值域范围;空间结构比AML和C++方法好,与地形相关性较高;效率远高于AML方法,由于增加了沟道提取,其效率稍低于C++方法。该方法可方便的应用于流域和区域尺度下的地形因子估算。
The factors of LS, slope length factor and slope steepness factor are general soil loss equation and modified universal soil loss equation USLE / RUSLE (universal soil loss equation, revised universal soil loss equation) factor. Based on slope hydrology and soil erosion theory, the principle, method and process of basin topographical factors are discussed. Considering the divergence and convergence of three-dimensional slope water flow, sediment deposition and channel truncation, based on the GIS technology, a method of estimating terrain factors based on multi-direction is proposed and the LS_TOOL tool is designed. Compared with the slope slope length calculated by the existing AML (ARC Macro Language) and C ++ methods, this method is compared in terms of spatial distribution and operation efficiency. The results show that the multi-flow method is used to calculate the range of range calculated by the reasonable and conforming topographic factors The spatial structure is better than AML and C ++ methods, and has a high correlation with topography. The efficiency is much higher than that of AML method. The efficiency of channel extraction is slightly lower than that of C ++ method due to the increase of channel extraction. The method can be conveniently applied to the estimation of the topographic factors at watershed and regional scales.