基于DEM的山顶点关联特征研究——以川东褶皱山系华蓥山主峰区为例

Research on the Correlation Characteristics of Peak Points Based on DEM:A Case Study of the Main Peak Area of Huaying Mountain of Folded Mountain System in East Sichuan

为分析山顶点空间关联特征及其揭示的地貌学含义,以川东褶皱山系华蓥山主峰区为研究区,基于ASTER GDEM数据,采用空间关联维、空间自相关方法对比分析了地貌特征尺度,计算了面积-高程积分(Hypsometric Intergral,HI)、地貌信息熵和高程剖面线,定量分析了地貌发育特征。关联维结果表明,华蓥山主峰区域山顶点在4.0~12.8km、12.9~35.3km两个区间内存在关联特征,关联指数分别为1.49和0.77;多尺度空间自相关分析表明山顶点自相关特征在4.24km处存在峰值;与关联维分析相比,空间自相关分析明确给出了不同分析尺度上的显著性水平,有助于特征尺度甄别。上述关联区间和特征尺度与研究区断层、断裂、向斜及背斜长度基本吻合。基于特征尺度对区域面积-高程积分、地貌信息熵和夷平面进行分析可知,华蓥山主峰区存在高程为1 300~1 400m、1 100~1 200m、600~700m的多级夷平面,上述结论基本与区域实际吻合。研究表明,基于山顶点进行空间自相关、关联维等分析,在分析地貌发育态势、解读深层次地貌学内涵方面有较好的应用潜力。

In order to analyze the spatial correlation characteristics of the mountain peak and its geomorphological significance,the main peak area of Huaying Mountain in the eastern Sichuan was selected as the study area.ASTER GDEM was used as the basic data,the spatial correlation dimension and spatial autocorrelation method were used to analyze the features of geomorphic development.The results of correlation dimension show that there are correlation characteristics for two sections of 4.0~12.8 km and 12.9~35.3 km in the main peak area of Huaying Mountain,and the correlation dimension is 1.49 and 0.77,respectively.The multi-scale spatial autocorrelation analysis shows that there is a peak value at 4.24 km for the mountain peak autocorrelation.Compared with the correlation dimension analysis,the spatial autocorrelation analysis shows the significance levels at different analysis scales,which is helpful for the feature scale screening.The above interval and feature scale are in good agreement with the fault,diagonal and anticline length of the study area.Based on the feature scale,the hypsometric intergral,geomorphic information entropy and planation surface are analyzed,which show that there are multi-level planation surfaces with elevation 1 300~1400 m,1 100~1 200 m and 600~700 m in the main peak area of Huaying Mountain.The research shows that the analysis of spatial autocorrelation and correlation dimension based on mountain peak has good potential in analyzing the development of landform and interpreting the connotation of geomorphology.