| With the construction of 'digital earth' and 'digital city', the development of UGIS (Urban Geographical Information System) is like a raging fire. The data are 'blood' of GIS system, the construction of the urban base geographical information database is influencing and restricting the construction and development of various kinds of city thematic geographical information systems, so close attention should be paid to the base geographical data gathering and base geographical database establishment at first in the construction of city geographical information system. The data source of urban base geographical information is various, the digital topographic map is important part among them, but because digital topographic map data purposes to make maps and must follows specifications of making topographic map strictly, which led to the fact that there are very great differences between digital topographic map data and GIS data, so making digital topographic map and GIS link up directly is difficult. So, this paper first analyzed the difference between the digital topographic map data and the GIS data in data use, data model, topological relation, semantic expression, and so on. .Because of these differences, there are difficulties in topographic map data integration for UGIS. In order to overcome these differences, this paper divided topographic map data integration into map data integration, style integration and attribute integration, classified the topographic map symbol, and gave the method of each kind of symbol integration. Then this paper presented new scheme of feature classification and coding, introduced the realization in such key technology as data conversion, data checking and data processing, etc., thus, which guaranteed to integrate the topographic map data into the base geographical information database smoothly. Finally, this thesis introduced the successful application of this method in establishing Lianyungang urban base geographical information database.
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