基于3S技术的地形起伏度与区域土壤侵蚀的相关性研究

地形起伏度直接影响着地面的径流变化,是导致土壤侵蚀的主要根源之一。分析两者相关性的前提是准确提取地形起伏度,而确定研究数据尺度下地形起伏度的最佳分析窗口是得出可靠结果的保障。在3S技术的支持下,运用均值变点法分析罗甸县基于DEM(空间分辨率为30m×30m)的最佳分析窗口,并依据2007年修正的土壤侵蚀分类分级标准估算研究区各样本单元的土壤侵蚀量,对两者进行相关性分析。结果表明:罗甸县在该尺度数据源下的最佳分析窗口为32×32,最佳统计面积为0.921 6km~2,实证了均值变点分析方法提取地形最佳分析窗口的可行性;地形起伏度与区域土壤侵蚀模数的相关系数为0.519 1,充分说明了作为宏观地形因子之一的地形起伏度是区域土壤侵蚀的主导因素之一。

Research for the Correlation Between Relief Amplitude and Regional Soil Erosion Based on 3S Technology

Relief amplitude directly affects the runoff variation of the earth surface,thus,it is one of the main causes of soil erosion.The premise of analysis the relativity between relief amplitude and soil erosion is to determine the best analysis window under the scale data to extract the relief amplitude.In this paper,we analyzed the best analysis window which resulted from DEM (30 × 30 resolution)of Luodian County in Guizhou Province through a method of mean change-point under the support of 3S technology.And according to the modified classification criteria of soil erosion in 2007,we estimated the soil erosion amount of each sample unit in study area.Finally,we analyzed the relativity between relief amplitude and regional soil erosion.The results show that the best analysis window under the scale data in Luodian County is 32 × 32,and the best statistical area is 0.921 6 km2,which effectively proves that using the mean change point analysis method for extracting the relief amplitude was feasible.Furthermore,the obtained correlation coefficient between relief amplitude and regional soil erosion modulus in Luodian County is 0.5 191,fully illustrating that relief amplitude as one of macroscopic topographic factors is one of the dominant factors in regional soil erosion.