Based On Grid DEM Extraction Terrain Features Of Research

Digital elevation model(DEM), which contains a rich variety of terrain structure characteristic information, such as feature points, characteristic line, the characteristics of the surface. The dot, the line and the face are as a skeleton of a building landform, and have a certain effect to control the landform. For example, the top of the mountain is one of the indispensable terrain feature points in the study of morphology. Ridge and valley line constitutes the relief the dividing line of change, which is also a water line and line of the catchment, not only has important significance on the study of landscape, and also has a special significance in engineering application from a physical standpoint. Implicit terrain feature information extracted from DEM data is one of the key problems of geological research.Terrain feature extraction method based on DEM data, which is mainly divided into three kinds according to the data source, namely rules based on grid data of topography and feature extraction, feature extraction based on irregular triangular mesh terrain and topographical feature extraction based on contour data. Due to the regular grid data which has the advantages of simple structure, this paper studies the rules of grid data of terrain feature extraction method.This paper introduces the domestic and foreign research status quo of the terrain feature extracting and related theory, and expounds the peak point, the relative concepts of ridge and valley line and extraction algorithm. And it is combined with the experimental data to improve the point of the top of the mountain ridge line valley line algorithm is analyzedExtraction at the top of the mountain, to improve the previous algorithm,some morphological characteristics through the analysis of the top of the mountain, we design a rapid extraction method is based on the analysis of the form the top of the mountain, the results show that the developed method can quickly and efficiently extract the top of the mountain, and DEM resolution and analysis the size of the window, which has an important influence for the extraction of the top pointIn this paper,the extraction of valley lines and ridge line is extracted based on the flow simulation method, mainly for the original DEM data preprocessing method was improved, and the extracted results using the positive and negative terrain correction, finally get the extraction results.The algorithm proposed in this paper, extraction of terrain features in conformity with the actual terrain. Extraction of terrain feature information for the study of the terrain structure research, the spatial distribution and cartographic generalization.However, the algorithm in the light of some theoretical and technical processing problems need to be further improved.