基于DEM和均值变点法的伏牛山区地形起伏度分析

Analysis of Relief Amplitude Based on DEM and the Mean Change-point Analysis Method in Funiu Mountain Area

以100 m分辨率的DEM为基础数据,在GIS技术和SPSS软件的支持下,采用邻域分析法,分别在29个大小不同的矩形分析窗口下提取伏牛山区地形起伏度,采用均值变点法计算出地形起伏度的最佳统计单元,最后绘制伏牛山区地形起伏度的分级图,并进行空间差异特征分析.结果表明:(1)运用均值变点法得到伏牛山区地形起伏度的最佳统计单元为11×11像元的分析窗口,对应的窗口面积为1.21 km^2.(2)基于计算出的最佳统计单元提取伏牛山区地形起伏度,并划分为5个等级.整体来看,伏牛山区以地形起伏度为200~500 m的中起伏为主,占53.27%,主要位于中高山地区;其次是地形起伏度为70~200 m的小起伏地形,占26.14%,主要分布在中低山地区;微起伏(30~70 m)和平坦(0~30 m)地区占18.85%,主要位于东南部和东部山麓地带;大起伏地区所占比例最小,仅为1.74%,主要分布在山脉主脊地带.(3)地形起伏度与坡度的拟合度高于与海拔的拟合度,且随海拔高度和坡度增加,其高值区所占比重分别呈逐渐增加趋势,表现出较强的海拔与坡度规律性.

Based on the DEM data(100 m resolution),with the support of GIS technology and SPSS software,the neighborhood analysis method is firstly used to extract the relief amplitude of the Funiu Mountain Area under 29 rectangular analysis windows of different sizes,and then the best statistical unit of relief amplitude is calculated by the mean change-point analysis method.Finally,the hierarchical map of the relief amplitude in the Funiu Mountain Area is drawn and the spatial difference characteristics are analyzed.The results show that:(1)The best statistical unit for obtaining the relief amplitude in Funiu Mountain is the analysis window of 11×11 pixels using the mean change-point analysis,and the corresponding window Area is 1.21 km^2.(2)Based on the calculated best statistical unit,the relief amplitude of the Funiu Mountain Area is extracted and divided into five levels.Overall,the Funiu Mountain Area is dominated by medium undulations with a relief amplitude of 200-500 m,accounting for 53.27%,mainly located in the middle and high mountains;followed by small undulating terrain with a relief amplitude of 70-200 m,accounting for 26.14%.It is mainly distributed in the middle and low mountains;the micro-undulation(30-70 m)and flat(0-30 m)areas account for 18.85%,mainly in the southeast and eastern foothills;the large undulations account for the smallest proportion,only 1.74%,and mainly distributed in the main ridge of the mountain.(3)The fitting degree of relief amplitude and slope is higher than that of relief amplitude and elevation,and with the increase of elevation and slope,the proportion of high value area increases gradually,showing strong elevation and slope regularity.