DEM地形复杂度指数及提取方法研究

Terrain Complexity Index and Its Derivation from DEMs

在充分阐述各种地形信息表达方式的基础上,提出了基于栅格DEM的地形复杂度指数的概念与计算方法。研究结果认为,DEM的地形复杂度指数是描述地形变化程度的综合指标。可以在一个3×3窗口中,通过提取栅格中心点与其邻域栅格所组成的相邻的空间平面之间的夹角来表示。根据在陕北黄土丘陵沟壑区1∶5万DEM的试验结果显示,该方法所提取的地形复杂度指数,可有效地描述该类DEM信息源的地面形态变化情况。该研究结果为进一步深入探讨DEM地形信息量的概念体系,以及地形信息量的空间分异规律及其随空间尺度(比例尺、栅格分辨率)变化的规律创造了重要的条件。

Based on an overall analysis of the methodology and technique for the description of terrain information representation, the TCI(Terrain Complexity Index), a new concept and quantification method for terrain complexity is proposed. TCI is a comprehensive index revealing the complexity and variation of true surface, which could be extracted via a calculation of an angle between two conjunct surfaces from a 3 by 3 cells based analysis window. Experiments shows that the TCI matrix derived from 1∶50 000 map scale DEMs could effectively represent the variation of the DEM based model surface. This research provides a good basis for constructing the conception system, as well as investigating the spatial distribution pattern of terrain information content.