On Urban Spatial Expansion and Analysis of Driving Forces in Chongqing City

Through introducing urban spatial expansion and compactness index, with the aid of remote sensing and geographical information system software, by means of pretreatment and analysis of TM image data and 2010 present situation of land utilization data in four time ranges(1980、1997、2005、2010), this article revealed evolution characteristics of Chong Qing city spacetime expansion. The results indicated that: Chong Qing spatial expansion expressed in time stages shows that Chong Qing after becoming municipality increased more quickly than before in expansion speed in general, it is mainly reflected at the urban expansion trend and intensity over time. Since development region is not the same in different periods, it leads to different districts having unbalanced characteristics in development, which is mainly reflected in various districts of the city having different development intensification, compactness and development model in the same period. The variation of driving factors mainly select socialeconomical factors, population growth factors and policy leading factors to be analyzed. A conclusion arrives that the speed of economic development cycle determines the city spatial expansion rate periodicity and city space structure differentiation form periodic, the national and regional policy leading, quick population increasing have an important effect on the Chong Qing urban expansion trend.