辽宁省侵蚀沟发育特性及地形分异特征

在不同层面对研究区数字高程模型(DEM)重分级,探讨地形因素对侵蚀沟发育的影响。以第一次全国水利普查侵蚀沟普查成果(2010年)与辽宁省第五次土壤侵蚀普查侵蚀沟普查成果(2015年)获取侵蚀沟分布数据,基于1∶50 000DEM获取侵蚀沟高程、坡度、坡向、坡长和空间分异特征。在地理信息系统(GIS)和遥感(RS)技术的支持下,分析辽宁省侵蚀沟发育特性与地形分异特征。结果表明:5年间研究区侵蚀沟密度增加0.02km/km~2,侵蚀沟高发区主要集中在辽西;70%以上区域密度变化值50m/km~2,大部分处于微度增加区;高程在325~350m时密度变化值最大;坡向上南坡、西南坡为密度变化高值区;坡度在1.5°~15°时密度变化曲线呈抛物线形,1.5°和15°时无明显变化;坡长在600~800m时密度变化值最大,坡长1 000m时密度变化值无明显差异。

Development Characteristics and Topographic Differentiation Features of Erosion Gully in Liaoning Province of China

In order to explore the influence of topographic factors on the development of erosion gully,regrading Digital Elevation Model(DEM) at different levels was conducted in the study area.The erosion gully distribution data were obtained from the results of the Erosion Gully Census in the First National Water Resources Census (2010) and the results of the Erosion Gully Census in the Fifth Soil Erosion Census In Liaoning Province (2015).Erosion gully elevation,slope,slope aspect,slope length and space differentiation were based on the 1 ∶ 50 000 DEM.This study analyzed the characteristics of erosion gully development and topographic differentiation in Liaoning province of China with the supported of geographic information system (GIS) and remote sensing (RS) technology.The results showed that the erosion gully density increased 0.02 km/km2 in the study area within 5 years,and the erosion gully mainly concentrated in the western Liaoning.The change value of the erosion gully density were less than 50 m/km2 in more than 70％ of the study area,most of them were in the micro enhancement zone.The change value of density was maximum when the elevation was between 325 m and 350 m.The change values of density of the south slope and southwest slope were the maximum.When the slope was between 1.5° and 15°,the graph of change density was parabolic,and there was no obvious change when the slope was less than 1.5° and more than 15°.The density change was the maximum when the slope length was between 600 m and 800 m,and there was no significant difference in density change when the slope length was more than 1 000 m.