Characteristics and Influencing Factors of Urban Land Expansion in Changsha
长沙城市土地扩张特征及影响因素

Based on the analysis about actual land-use map of Changsha City in different times, this article analyzed the characteristic of urban spatial expansion of Changsha from time sequence, spatial form and structure evolution systemically by studying indexes such as city land-use structure proportion, expansion intensity index, economy flexibility index, population flexibility index, compaction degree changing index and so on. And then it discussed the dynamic mechanism of urban land expansion by integrating the regional socioeconomic development situation and many aspects such as physiographical environment, population growth and economic development, traffic infrastructure, planning and regional development strategies and system innovation. The research indicated that the urban land expansion speed and intensity got higher step by step in Changsha from 1949 to 2004, the whole trend became more and more reasonable, and the expansion form changed from a single external expansion to a combination form of external and internal expansion, from a circular or linear continuous form to a speckled or clustered discontinuous pattern. Overall, the urban land expansion of Changsha is a phasic, diversified and complex process. And no matter what the stage is, it is an organic system containing multiple speed, pattern and shape, which are driven by multiply impetuses. The dominant features in different stages presented clearly because of balance and fluctuation between different forces, and the existing urban land border and shape were formed finally under the joint efforts of these phasic forces.