基于DEM和GIS的修正通用土壤流失方程地形因子值的提取

 地形是影响土壤侵蚀的重要因子。以修正通用土壤流失方程中的地形因子为研究对象,以黄土高原延河流域县南沟5m分辨率的DEM为数据源,在ArcGIS软件平台下,实现对地形因子LS值的提取。对提取后的LS值和LS值分布进行检验分析,结果表明:以5m分辨率的DEM为数据源,采用适合该地区的修正后的LS值的算法,在ArcGIS支持下,可以获得较准确的LS值。研究结果可以为区域土壤侵蚀的地形因子研究提供数据支持,为更大区域尺度转换提供数据匹配基础,同时,为土壤侵蚀在区域尺度上进行预测评价提供方法引导和技术支持。

Extraction of RUSLE-LS Factors Using DEM data and GIS Techniques

The assessment and prediction of soil erosion at regional scale is of great importance to the sustainable land use planning and ecological restoration.Yet reliable prediction of soil erosion depends on the factors affecting the soil erosion,just as described in RUSLE.As one of the important factors affecting the soil erosion,topographic factor may have impact on the soil erosion in many aspects such as the redistribution of rainfall and runoff accumulations and its velocity,and many studies have been done on it.However,most of studies just focused on the impact of topographic factor on soil erosion,only few studies have been done on the extraction of topographic factor,and little on the validation and comparison of topographic factors extracted.In this paper,the topographic factor(LS) for RUSLE(revised universal soil loss equation) using powerful DEM and GIS techniques was extracted for Xiannangou catchment,Loess plateau,aiming at providing technological support for the assessment and prediction of soil erosion on regional scale.The results showed that the LS values extracted from the fine DEM with a resolution of 5?m,if choosing a right algorithm,are reasonable,reliable and practicable.It can provide a reference for the further study of LS factors on regional scale and providing a basic data for scale transform among different scales.