基于DEM的商洛市水土流失分析

Analysis of soil and water loss in Shangluo Cityon the basis of DEM

目的运用ArcGIS软件对商洛市地形因子进行分析,探讨其对水土流失的影响。方法以商洛市为研究区域,采用数字高程模型(Digital Elevation Model,DEM)数据,选取坡度、坡长、沟壑密度及地表切割深度4个指标对水土流失程度进行分析。结果商洛市急陡坡主要集中在西南部的镇安县及周边,缓倾斜坡主要集中于商洛市北部的洛南县及周边区域;商洛市中部的商州区、丹凤县、柞水县东部及山阳县东北部等地区坡长均在35m以上,其它区域坡长较短;商洛市西南部大部分区域的地表切割深度在200m以上,其它区域地表切割深度较小;商洛市沟壑密度均值1.20km/km2,密度较小。结论商洛市中部及西南山区水土流失较重,坡度、坡长及地表切割深度3个地形因子对商洛市水土流失的影响显著。

Purposes— To explore the influence of topographic factors on soil erosion in Shangluo City with ArcGIS.Methods— Four indicators, namely, cutting slope, slope length, gully density and surface depth were analyzed with Digital Elevation Model （DEM）.Results— The steep slope of Shangluo City was mainly centered on Zhen’an County and the surrounding area in the southwest of the city, and the gentle slope was mainly concentrated on Luonan County and the surrounding area in the north of Shangluo City. The slopes in Shangzhou District, Danfeng County are more than 35 m long, but the slopes in other regions are shorter; the surface cutting depth of most areas in the southwest of Shangluo is above 200 m. And the surface cutting depth in other regions is relatively small. The mean density of gully in Shangluo City is 1.20 km/km 2 , and its density is small.Conclusion— The soil erosion in the central and southwestern regions of Shangluo City is heavy. Three terrain factors such as slope, slope length and surface cutting depth have significant influence on soil and water loss in Shangluo City.