地表高程剖面特征及其在起伏度分析中的应用——以平行岭谷区华蓥市为例

Multi Scale Analysis of Elevation Profiles and Its Application in Research of Relief Amplitude of Terrain:A Case Study in Huaying County Based on ASTER GDEMs

针对确定高分辨率、小区域地形起伏度最佳求算区域中存在的不确定性,提出了分析地表高程典型剖面的多尺度特征,继而探索其在确定最佳求算区域中的应用适应性的方法。利用多尺度DEM分析县域地形起伏,以川东平行岭谷区华蓥市为例,基于ASTER GDEM数据,提取高程剖面线。Morlet小波多尺度分解显示,在20-27（600-810m）及42-46（1 260-1 380m）窗口区间小波方差呈现峰值特征。为验证多尺度特征及其在确定地形起伏度最佳分析窗口中的应用,基于30m及90m分辨率的DEM运用邻域统计法求算地形起伏度。均值变点法表明地形起伏度最佳分析窗口分别为27×27（810m）、17×17（1 530m）,单元面积分别为0.65km^2、2.34km^2,接近小波峰值区间,90mDEM求算的地形起伏度更接近于实际情况。实验表明,高程剖面分析是研究岭谷区地形多尺度起伏特征有效方法之一;其指示的特征尺度,可以与变点法确定的起伏度分析窗口相互对照。

In view of the problem that the suitable window size of the relief based on the high resolution and the small area is uncertain, the multi-scale feature of the typical profile of surface elevation is proposed, and then the method of application adaptability in the determination of the suitable window size is explored. In this paper, ASTER GDEM is used as the basic data source, and the study area is located in parallelism range-gorge in eastern parts of Sichuan province. Based on ArcGIS, two typical elevation profiles are interpolated. The results show that there are two peak values in the windows range of 20 ？27 （600-810 m） and in 42 -46 （1 260 -1 380 m） while 30 m and 90 m resolution DEMs are used to extract the relief by neighborhood analysis and the suitable window size are 27×27（810 m） and 17×17（1 530 m） with areas 0. 65 km^2 and 2. 34 km^2 which is close to the result of wavelet analysis. We recommend that 90 m resolution DEMs will get the better depiction of the regional relief. The experiment also shows that the critical scales of elevation profiles can be used in the relief amplitude.