Multi-Scale DEM Generalization Processing in Different Landform Areas

Abstract

As a special kind of image, the grid-based digital elevation model (DEM) is directly related with the landform and topography feature. In the real word, there are various landforms, and the results of different methods for DEM processing vary greatly. However, the discussion of using different methods in different landform areas in DEM generalization is needed. Numerous methods have been proposed previously for DEM generalization without taking topographic factors into consideration, and the setting of threshold value of most algorithms is very subjective. Therefore, we investigate the DEM generalization, using two methods (z-tolerance method and compound method) in different landform areas and propose a new way for threshold values setting in generalization. The results show that the method we proposed is feasible and the compound method offers a better performance over z-tolerance method in most conditions, especially when comparing their performances of keeping streamline shape.