江苏省城市经济影响区格局变化

The Evolution of Urban Economic Effect Regions in Jiangsu Province since 1978

首先运用Mann-Kendall方法将1978年改革开放以来江苏省区域经济发展划分为三个不同阶段。然后采用城市中心性指数和交通时间成本对传统势能模型中的城市规模和距离因子进行了修正,并运用GIS的栅格算法得到主要年份江苏省不同等级中心城市的经济影响区范围,分析其格局变化特征:①南北格局向东西格局转变;②南部经济影响区向北扩展;③苏南地区新中心城市的出现。最后,探讨了江苏省城市经济影响区的变化机制,认为交通轴线的发展状况、经济发展水平和社会生产要素投入差异是导致城市经济影响区格局变化的主要原因。其中,不同的交通轴线对周边地区带动作用差异明显;经济发展水平则显现出苏南一枝独秀,苏中、苏北趋同发展的趋势;生产要素投入中资本、技术投入对经济影响区的格局变化起主导作用。

According development process in to the theory of abrupt climatic change, the regional economic 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.