黄土丘陵沟壑区地表过程响应单元划分及其地形特征提取

Division of response units to earth surface processes and their extraction of topographic characteristic in the Hilly-gully Region of Loess Plateau

地表过程解析与调控是保障人与自然和谐相处的重要途径,高效、合理地划分地表过程响应单元则是开展地表过程研究的重要前提。针对黄土丘陵沟壑区土壤侵蚀的地形地貌分异特征,提出在小流域内以沟谷线、山脊线、分水线和沟缘线相互交叠,构成具有相对均一坡向、坡度与坡位的地表过程响应单元,在ArcGIS9.2中,以Hc-DEM为基础数据,通过确定沟谷线、山脊线、分水线和沟缘线的提取方法,以及响应单元平均坡度、整体坡向、面积与周长等地形特征的测算技术,实现地表过程响应单元的快速划分及其地形特征的高效提取。研究结果对促进黄土丘陵沟壑区以土壤侵蚀为代表的地表过程研究具有重要的基础意义。

The analysis and regulation of earth surface processes is an important way to ensure human living in harmony with nature.Further,dividing the response unit to earth surface processes efficiently and reasonably is an important premise for the earth surface processes research.Aim at the topography differentiation characteristics of soil erosion in the Hilly-gully Region of Loess Plateau,we put forward that the gully line,ridges line,divide line and shoulder line of valleys were extracted by overlapping in a watershed,which will benefit to make up earth surface processes response units with relatively homogeneous gradient,aspect and position of the slope.The extraction method of the gully line,ridges line,divide line and shoulder line of valleys form hydrologically correct DEM data were presented separately,and measuring technology for the topographic characteristics of response units to earth surface processes such as average gradient,overall aspect,area and perimeter were presented in ArcGIS9.2 software.It can be concluded that fast division of response units to earth surface processes were finished and their topographic characteristics were effectively extracted.The results in this paper will play an important basic function for promoting the research of earth surface processes in the Hilly-gully Region of Loess Plateau.