Digitalization Of City Planning -GIS Of City Land Evaluation And Its Key Technologies

City is the center of economy,politics and culture in a nation or district.City plannning takes a very important role in keeping the development of the city healthily and rapidly. According to the general rule of city developmnet, our country's citified level will increase rapidly in recent year, which bring higher request for city planning. But now, in our country city planning is still keeping its traditional hand model and can't reach the request of city's development.The thesis of this paper derived from the national SHIWU R&D project "digitalization of city planning and construction,administration and service". This paper aimes to study on digital method and computer realization of the city planning decision support system .The detail research works as follows:(1) Quantification and digitalization method of city land suitability evaluation. (2) Quantification and digitalization method of city land economic benefits evaluation. (3) Quantification and digitalization method of city land environmental evaluation. (4) Development of a system to apply the quantification and digitalization methods.The research results of this paper includes:In the land evaluation aspect, this paper study on the mature method that used widely in city planning and its factor hierarchy, and put forward the data model and method model based on GIS raster data format and quantification method of factors. That model realizes the land evaluation by grid overlay, which is characteristic of its ability to adapt to whichever evaluation factor hierarchy dynamicly.In the land economic intrest and environment interest evaluation aspect, this paper present a model based on GIS vector data format and MIS data integration.Successfully developed the city land evaluation GIS, which apply those models upward and has been applied in some city planning projects. GIS of city land evaluation based on these models has been applied some projects of city planning. Facts show that Models in this paper could represent the land's real state well and can provide decision support for city planning.