Multi-scale DEM (digital elevation model) construction method considering topographical semantic information

The invention discloses a multi-scale DEM (digital elevation model) construction method considering topographical semantic information. The method comprises the following steps: calculating a DEM point location local geometric importance degree TSIlocal(terrain significance index) for a DEM point location local importance degree; determining a semantic importance degree weighing allocation scheme of topographic feature points according to the type of the topographic feature points and topographic hierarchical structures, and calculating a DEM point location global semantic importance degree TSIglobal; measuring and extracting a DEM point location comprehensive importance degree index TSI; determining a TSI threshold value according to a corresponding relation between the scale size of a reconstructing target DEM which is obtained by comparison and the threshold value of the comprehensive importance degree index TSI; choosing a candidate topographic feature points; performing spatial interpolation, and completing target scales to construct DEM. According to the method, high-grade main geomorphic elements are preferentially reserved, and secondary-grade geomorphic elements are gradually abandoned, so that topographical framework features under different scale conditions can be kept, maintaining the consistency between a multi-scale DEM construction result and the application thereof is facilitated, and the practical effect of multi-scale DEM construction technology is effectively improved so as to meet multi-scale DEM application demand of different social levels.