Updated Gis-based Urban Benchmark Premium

Since the end of 1980s, the system of land use has been reformed that the land can be dealt and must be paid in finite time rather than cann't be dealt in China. The transfer of the right of land use is beconing legal, open and regular instead of spontaneous, intangible and out-of-order. Land has become properties, so land value must be appraised avoiding state properties lost. Chinese scholars are studying Chinese system of land evaluation aimed at the character which land market hasn't developed and the market is various. Chinese characteristic land evaluation system is set up step by step . Benchmark land-price which is a key part of the system of Chinese urban land price is one of open land price of the government and the base of land evaluation, so the renewal of benchmark land-price is very necessary with the change of land use and management and land market. So the method of the renewal of urban benchmark land-price becomes one focus of current researches of land price.The purpose of this renewal study of benchmark land-price is to shorten the time of land evaluation and make the gradation and evaluation of urban land more objective, scientific and practicable assisted with GIS in case of Songyuan city in JinLin province , aimed at disadvantages of urban benchmark land evaluation ,such as the long time of appraisal, benchmark condition being different, the connotation being ambiguous, the land price system being faulty. The result shows not only the gradation of urban and the renewal of benchmark land-price of Songyuan has been finished, but also the database related to land price has been set up based on SuperMap GIS which lays a foundation for the dynamic renewal of benchmark land-price. Additionally, the remarkable achievements has been made, such as :1) The result of gradation of urban land is comprehensive and systemic. Not only the maps of gradation and the maps of isoline of all the gradation factors are automatically created, but also the borderlines of gradation are optimized. There are 68788 cell griddings of 30×30m~2 which was created automatically in area of 60.48 km~2(including the city zone and the laying out zone) of Songyuan gradation of urban land. The maps of land gradation of comprehension, commerce, housing, industry are created in method of classified gradation. In order to apply better, the borderlines of land gradation are made into smooth which keep owner's land complete. So rich achievements are made , such as 12 maps (3 series) of urban land gradation of Songyuan, 4 maps of total scores of urban land gradation of Songyuan, 16 isoline maps of gradation factors.2) The grade benchmark land-price system is set up more completely., the system land factors should be different because the local conditions are different in which influence on the different land use type. The benchmark land-price are classified according to types, grades and...