规则格网DEM坡度坡向算法的比较分析

DEM的主要用途之一就是提取坡度和坡向。目前基于格网DEM的坡度坡向算法比较多，正确分析和评价现有算法是当前较为关心的问题。通过对格网DEM的算法进行了简要的归纳，然后对坡度坡向算法进行了理论分析。并通过实验对相关的结论进行了验证。本研究澄清了目前有关DEM坡度坡向算法中存在的一些问题，对实际应用有一定的指导意义。

Study on the Accuracy and Algorithms for Calculating Slopes and Aspects Based on the Digital Elevation Model

Slope and aspect are the most frequently used terrain parameters in geoscience models, they can not only indirectly describe the shape and structure of a terrain, but also are the basic parameters in the hydrological models, monitoring and analysis of landslides, surface material movement, soil erosion models, land use planning, etc. However, there are some different viewpoints and even contradictions in the accuracy and algorithms of slope and aspect due to the differences in the sources of errors, analysis and evaluation methods. In this paper, the errors in calculating slopes and aspects with digital elevation model (DEM) are theoretically analyzed, and the conclusions concerned are verified with the experimental data so as to clarify the contradictions in calculating slopes and aspects. It is considered that the sources and characters of the errors in calculating slopes and aspects with DEM should be differentiated, and the evaluation of the algorithms should be carried out in the objective and quantitative environment with the comparable objects.