基于变点分析的地形起伏度研究

Analysis on Relief Amplitude Based on Change Point Method

探讨利用DEM数据分析地形起伏度的方法,以及针对不同比例尺的DEM数据分析地形起伏度时,寻求最佳统计单元的途径。结果表明,新疆局部地形起伏度较大,总体地形较平缓;地形起伏度随网格尺度的增大而增大,并且存在一种对数关系。基于1∶25万DEM数据提取地形起伏度时,2.56 km2是最佳统计单元。均值变点分析方法在确定最佳统计单元方面具有普适性。

Extracting relief amplitude provides an effective means for the access to surface information and the quantitative analysis of the terrain. In this paper, the aim is to search a method of extracting relief amplitude by DEM. An approach to obtain the optimum statistical unit when analyzing relief amplitude with different scale data is discussed. The best statistical unit is calculated by the raighborhood analysis and mean of change point method using the 1 ： 250 000 DEM data of Xinjiang. The result shows that the relief amplitude in Xiniiang is very high in part, but it is very smooth as a whole. Relief amplitude increases with the grid scale, and there exists a logarithmic relationship between them. 2. 56 km^2 is the optimum statistical unit when analyzing relief amplitude with 1：250 000 DEM. Change point method is general and suitable for calculating the optimum statistical unit.