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【Abstract】 Existing visualization systems of global-scale spatial data mainly focus on the integrating representation of DEM and image data on sphere,but less are capable to integrate vector and terrain data effectively.Degenerate Quadtree Grid(DQG) is employed to model the global DEM with the method of transferring DQG into triangles in this paper.The algorithm of mapping vector data onto DEM is developed based on geometry computation.An experiment of integrating GOTOP30 and country boundary data is carri...