基于地形梯度的土壤侵蚀强度分布特征研究——以钦江流域为例  

Research on Spatial Distribution Characteristics of Soil Erosion Intensity Based on Terrain Gradient——A Case Study in Qinjiang Watershed

作　　者：高峰[1] 华璀[1] 卢远[1] 陶艳成[2,3] 李卫宁[4] 

机构地区：[1]广西师范学院资源与环境科学学院,南宁530001 [2]广西科学院广西红树林研究中心,广西北海536000 [3]广西红树林保护与利用重点实验室,广西北海536000 [4]桂林理工大学南宁分校土木与测绘工程系,南宁530001

出　　处：《水土保持研究》2014年第2期22-26,共5页Research of Soil and Water Conservation

基　　金：广西北部湾经济区城市化与生态环境交互耦合机制研究(210167);广西教育厅项目(201106LX297)

摘　　要：地形因素是影响土壤侵蚀空间分布格局的重要因素之一，以钦州流域为例，应用DEM数据，在ArcGIS10．1空间统计分析模块下，采用高程梯度、坡度梯度和地形位梯度三种方法对比研究，通过分析不同土壤侵蚀强度存三种地形梯度上的分布指数，揭示研究区域的土壤侵蚀强度分布的模式及其与地形因素之间的对应关系。结果表明：（1）在高程和坡度梯度上，中度、强烈、极强烈和剧烈主要分布在1～2地形梯度上；在地形位梯度上，微度侵蚀在1级区域上占据了优势地位，分布面积最大，这与在高程和坡度梯度上的分布恰恰相反。（2）对三种方法的比较表明，地形位综合了高程和坡度的信息，可以反映土壤侵蚀强度随地形变化的分布趋势以及土壤侵蚀强度的分布特征。（3）研究可为区域土壤侵蚀强度空间分布格局和水土保持规划的研究提供一种可行的定量分析方法。Terrain is not only one of the important factors affecting the spatial distribution pattern of soil erosion, but also a prerequisite for soil erosion assessment and land evaluation. A good understanding of the relationships between soil erosion intensity class and terrain gradient is essential for soil and water conservation planning. In this paper, elevation, slope, and terrain niche were conceptually divided into 13 classes, which were used to describe the terrain difference across the study area, Qinjiang watershed in Guangxi. The nondimensional distribution index was used to examine characteristics of soil erosion intensity. Using DEM and other materials from field survey based on the spatial statistic analysis module in ArcGIS 10. 1, the distribution pattern of soil erosion intensity and their relationships with terrain factors in the study area were revealed by analyzing the nondimensional distribution index for different soil erosion intensity classes on varying terrain gradients. Results showed that： （1） moderate erosion, intensive erosion, extremely strong erosion, and severe erosion distributed mainly on the 1-2 terrain gradients at the elevation and slope gradi ents. The distribution index of mild erosion occupies a dominant position on the 1 terrain gradients at the terrain niche gradients, whereas the micro （2） comparing the three methods, the erosion terrain in the elevation and slope gradients shows an opposed trend; niche was found to be able to explicitly show distribution trends of sgil erosion intensity with variations in terrain, and the terrain niche indexseems to be more effective to refteet d.istribution characteristics of soil erosion intensity in that the terrain niche synthesizes information of both elevation and slope; （3） this study provides a feasible quantitative method for the spatial pattern of soil erosion intensity and soil and water conservation planning.

关 键 词：土壤侵蚀强度 坡度 高程 地形位指数 分布指数 

分 类 号：S157[农业科学—土壤学]