Urban Economic Effect Region Spatial Evolution:Taking Yunnan Province as an Example

This paper analyzes the urban inequality of Yunnan Province during 1990 to 2004. The authors find that the differentiations among the comprehensive strength of cities of Yunnan tend to increase since the 1990s. When most of the cities in Yunnan sprawl slowly and change unobviously, only a few highest-rank cities are in the process of polarization, presenting clear central-peripheral effects. Thus, the urban economy organization that has influenced the evolution of the urban-regional structure has demonstrated these following features:(1) The urban economic effect region (UEER) in Yunnan was splitted into the discretization patterns that they were fragmentized in geography before the 1990s;(2) since the 1990s, with the fast pace of the regional industrialization and urbanization as well as the growth and the radiation of the communication network of transportation, the medium-and small-sized cities have been agitated. Furthermore, with the unbalanced spatial expansion and the shrinkage of UEER, that is, UEER has gradually transformed from a simple discrete distribution structure into a three-layered-nesting structure. The UEER of Yunnan begins to reveal the obvious spatio-temporal order:from the miniature discrete patterns and the transitional patterns to the three-layered-nesting structure patterns. Finally, based on this spatio-temporal evolutive sequence, the authors analyze the three types of the spatial spread of the UEER in different spatio-temporal combinations:dominant-direction spread type, the multi-direction spread type and the abutting spread type.