城市群城市用地扩张时空特征及驱动机制研究——以长株潭城市群为例

探讨城市用地扩张时空特征及驱动机制,对制定有效的城市群高质量发展规划和国土空间规划至关重要。以城市群为研究对象,运用扩张强度指数、景观扩张指数以及SAR Probit模型对长株潭城市群城市用地时空特征及驱动机制进行研究。结果表明:(1)城市群处于不同的发展阶段,其城市用地扩张表现出不同的特征,研究期内城市群的城市用地扩张强度呈先加强后减弱的趋势,并表现出"中心-边缘"扩张空间格局。(2)城市群城市用地空间扩张类型整体上呈现扩散向集聚转变态势,符合"扩散-集聚"的城市增长理论。1995～2010年以飞地式扩张类型为主,2010～2018年边缘式扩张类型替代飞地式成为主导类型。(3)社会经济、地理、可达性以及溢出效应等因素综合作用,对城市用地扩张产生了正向和负向影响,判定出社会经济和溢出效应因素为影响城市用地扩张的主控因素,并提出了城市群城市用地扩张的"四力"驱动机制框架。以上研究发现有助于更好地理解城市群的城市用地扩张过程,能够为长株潭城市群一体化和高质量建设提供科学依据。

Study of Spatio-temporal Pattern and Driving Mechanism of Urban Land Expansion in Urban Agglomeration:A Case Study of the Changsha-Zhuzhou-Xiangtan Urban Agglomeration

Abstract：The researches of the spatial and temporal characteristics as well as driving mechanism of land expansion of Changsha-Zhuzhou-Xiangtan urban agglomeration, a typical agglomeration in Hunan province, is of great benefit to formulate the high-quality development planning of the urban agglomeration and land spatial development planning.A variety of analysis methods including Expansion Intensity Index, Landscape Expansion Index and SAR Probit model were used to study the characteristics of urban land expansion and driving mechanism. The results indicate: (1) The characteristics of urban land expansion varied when the urban agglomeration was at different stages. Its intensity was strengthened first and weakened later, forming a spatial pattern of “core-periphery” expansion. (2)The urban expansion process of urban agglomeration changed from diffusion to coalescence, which was consistent with the urban growth theory“diffusion-coalescence”.The growth type of leapfrogging was dominant during the urban land expansion period during 1995-2010;the growth type of edge-expansion,became the mainstream during 2010-2018.(3)With the factors like socio-economy, geography, accessibility and spillover effects, dual impacts were made in the process of urban land expansion.The socio-economy and spillover effects turned out to be the dominant factor controlling the urban land expansion. Furthermore, this paper puts forward a driving mechanism framework of land expansion, which was in the name of “four forces” model. These research findings will do good to the better understanding of urban land expansion of urban agglomerations and provide a scientific theory for the integration and construction of Changsha-Zhuzhou-Xiangtan urban agglomeration.