Study Urban Extension Spatial Differentiation Based on Multi-temporal Satellite Remote Sensing Images

Taking Yiwu city for example, dividing the urban region into 4 spatial units that is northeast, northwest, southeast and southwest. Using multi-temporal satellite remote sensing Images and geography information system, the space clustering and historical shape for the city land use expanding from 1970 to 2004 were studied in this paper. The results indicated the spatial differentiation law and the driving force of land using extension. Before 1991, the urban extension driving force is the commodity market agglutination. From 1991 to 1997, market irradiation appeared with the urban area agglutination, the construction of specialty markets prompted the laminated plate extension of the city. After 1997, the burst Yiwu city urban extension was driven by construction of new dwellings, construction of new public facilities and the outmigration of public facilities. The research in this paper indicated that the driving force of commerce was important in the process of Yiwu urbanization.