The Evolution of Urban Economic Effect Regions in Jiangsu Province since 1978
江苏省城市经济影响区格局变化

According to the theory of abrupt climatic change, the regional economic development process in Jiangsu province since 1978 is divided into three periods in this paper. Then the paper employs urban centrality index and time cost for transportation, instead of the city scale and the distance factor, to modify the original potential model. Based on the grid arithmetic of GIS methodology, the paper identifies the scope of urban economic effect regions (UEERs) for central cities at different ranks in Jiangsu province of the main years. Accordingly, Jiangsu province can be separated into different ranks of UEERs. Consequently, the characteristics of UEERs in Jiangsu province since 1978 can be summarized below:(1) the spatial structure changes from South-North to East-West;(2) the UEERs in the southexpands towards north;and (3) the new central cities in southern Jiangsu province occur. Furthermore, the mechanism of evolution of UEERs in Jiangsu is also analyzed in this paper.The development of transportation axes, the diversities of economic development level and the disparities among the input of social production factors are the three main reasons accountable for the changing patterns of UEERs. The effects of transportation are measured by density of transportation network of each county or city which is calculated by different weighed values for highways, expressways and so on. The economic development level measured by GDP per capita is a direct way to reflect the disparities of capability for central cities. And the influence of social production factors is weighed by analyzing the index of total population, fixed assets investment per capita and the number of the labor force. It is concluded that transportation axes play the most important role in the spatial structure formation of UEERs among the three factors;besides, the capital-intensive factor input has greater influence on UEERs than the labor-intensive one does to a great extent.