DEM Based Division Of Mountainous Topography Entities

In the last century60s,DEM has become an important branch of surveying and mapping. Digital elevation model (DEM) is the most important spatial basic data of geographic information system data for geological simulation and analysis.Geographic space object has the uncertainty of the objective world itself and limitations and uncertainty of human cognitive process. People have different cognitive understandings of mountain. Based on the ontology and the geography ontology, we draw mountain ontology. Based on the digital elevation model mountainous topography entity and mountain ontology, we advanced the fuzzy probability field. Through the confirmation of the fuzzy subordinate relationship of mountains, the mountain can be recognized clearly. With the use of the multi-scale DEM data, we discussed the relief degree of the mountain. In the paper, the main research content and the main achievements are as follows:1) Based on the understanding of the DEM, from the perspective of "Digital Mountain", we analyzed the cognition of geographical spatial object. With the use of ontology and combined with the geographic ontology, we analyzed the mountainous cognition, and obtained the mountain ontology concepts.2)Based on DEM data,we analyzed the mountain landscape entity in Kangding area and the object oriented method, and the spatial data projection transformation in the GIS data classification. Based on the uncertainty of geographical spatial object, we obtain the fuzzy probability field concept based on fuzzy membership degree theory. the fuzzy probability field model are designed. We have carried on the exploration about landform known from micro grid to macro qualitative.3)Based on multi-scale DEM, using the cognitive structure of mountainous topography, mountainous cognition and terrain features analysis. We catalogued peaks of Kangding study area and further analyzed the features of mountain distribution density. With five different spatial resolution DEM, we obtain the best threshold analysis window of relief degree in Kangding area on various scales and classifications of the mountain.