3-D GEOLOGICAL MAP COMPILATION BASED ON MAPGIS AND SURFER

Traditional geological maps are usually made with 2-D technology. With the development of mapping technology and the application of mapping software, numerous kinds of information could be integrated based on spatial locations. The technology as such has become more and more popular. 3-D map is widely used in marine geology because of its better visual representations and abundant levels. MapGIS and Surfer are the two GIS software popular in geological society due to their own advantages. This paper discusses the production of 3-D geological map taking the Shanghai sheet as an example using both the MapGIS and Surfer software based on DEM. There are many islands distributed in study area. There is no survey data around the islands, and the islands become deep holes in the 3-D map, which will certainly cause severe distortion of real topography. In our practice, the island boundary line is assigned to zero using the line elevation extraction in MapGIS. Then using the depth data and the zero data we can make interpolation to build the marine DEM. The topographic map and geomorphological map made with MapGIS could be superimposed to the 3-D map in Surfer to produce a 3-D geoloical map.