Multi-Scale DEM Representation And Terrain Analysis Effects Based On Wavelet Analysis

The information age is already upon us, there is a highly demand in different kinds of geo-spatial data, the corresponding demands in data analysis and display of multi-scale DEM are rising, which has become an important issue in GIS application. Multi-resolution analysis in wavelet theory provides a basic to build and maintain a spatial model which can be used to express the nested multi-scale geo-spatial sub-sequence and scale-dependent spatial data. We chose loess plateau as the study area and made a multi-scale automatic synthesis and continuous expression by the method of binary wavelet. Based on the analysis of wavelet theory and multi-resolution analysis, analyzing DEM data structure and terrain morphological structure, we used an optimal DEM sampling area to express 1:10000 DEM by wavelet function. By the contrast analysis by 1:50000DEM, DEM data can reach to a high precise by the wavelet function. Then, we made a multi-scale DEM and national 1:50000DEM to terrain analysis effects by re-sampling. The results indicated: multi-scale DEM produced by wavelet is scale independent, DEM sequence is terrain structure independent, and terrain parameter enjoys a high precise. Finally, we analyzed the suitable range of multi-scale DEM expression, the DEM of 1:10000 scale and 5 m resolution have better accuracy and reasonable Significance terrain information. In this paper, it provides a reference processing model of scale dependent on the establishment of a multi-scale topographic analysis capability multi-scale DEM based on wavelet transform, the conformation of scaleless GIS has extremely important scientific significance This paper based on the sample of the Loess Plateau, it also has established the foundation of multi-scale analysis of the Loess Plateau landscape and digital analysis of the Loess Plateau.