县域LS因子提取与分析——以陕西长武县为例

LS计算是利用USLE等坡面模型进行流域与区域土壤侵蚀评价与制图的基础,在对第四次土壤侵蚀普查试点县进行LS因子提取工作的基础上,以长武县为例,总结介绍县域LS因子提取的主要技术环节、主要技术要点及工作流程,并对LS因子提取结果进行评价和分析。从提取的坡度、坡长、LS因子的统计和空间分布特征看,基本可反映该地区的塬面、塬坡、现代沟坡和川地等地貌特征。结果表明,利用前期的理论研究和技术开发,可提取LS因子,该因子具有一定科学性,可满足土壤侵蚀的宏观评价要求。

Extraction and Analysis of LS Factor at County Scale——Taking Changwu County as an Example

It is essential to calculate LS factor for soil erosion assessment and mapping based on slope models at watershed and regional scale,such as USLE.Based on the LS factor extraction work in the experimental counties of the Fourth National Soil Erosion Survey,this paper took Changwu County as an example and summarized its main technical links,key technologies and workflow.From the statistical and spatial characteristics of extracted slope,slope length and LS factor,the extracted factors can basically reflect the plateau,plateau slopes,modern gully and plain ground features of this area.The result of the LS factor extraction had been assessed and analyzed too.It shows that LS factor can be rationally extracted based on our prior results on theory and technology,and the extracted factor can meet the need of soil erosion assessment at macro-scale.