The Change Characteristics And Formation Mechanism Of Urban Construction Land In Changsha

Since the 21 st century,China's urbanization process has made remarkable achievements.As the carrier of urban population and economy,urban construction land has shown a rapid development trend.However,with the rapid changes in urban construction land,there are some contradictions such as the surge demand and limited supply,unbalanced land structure and chaotic layout in urban construction land.Thus,it is necessary to make scientific use of urban construction land.Taking Changsha as the research object,this paper uses remote sensing data and POI data to analyze the change characteristics of the scale,layout and form of urban construction land from 1990 to 2017.Meanwhile,it also summarizes the influencing factors and formation mechanism of urban construction land change on the basis of existing research.The specific conclusions are as follows:(1)The expansion speed and intensity of urban construction land in Changsha show the characteristics of increasing first and then decreasing,and the maximum expansion speed and intensity in the medium term.The expansion speed and intensity of each district(county)in Changsha are different in different periods,which is closely related to its urbanization level and construction foundation.(2)The center of gravity of urban construction land in Changsha has experienced a dynamic change process from east to north to west,and the expansion direction has experienced a spatial transformation process from SE to W and SW.The residential land,public management and public service land,commercial service facility land,and industrial land of Changsha are arranged in the form of "single core";the green land and the square land of Changsha are arranged in the form of "dual core";the transportation facilities land of Changsha is arranged in the form of "multicore".(3)The urban construction land in Changsha mainly shows in the form of "cluster" and "Star".The expansion mode has undergone the process of filling-epitaxial-filling.The compactness index of urban construction land in Changsha decreases year by year.The good overlap between the non compactness feature and the extension expansion shows that the extension expansion often leads to the loose urban construction land,resulting in the non compactness of urban land.(4)Based on the existing research results and the actual development of Changsha,this paper sums up the influencing factors of urban construction land change,which are natural geographical conditions,social economic factors and policy factors.Using the stepwise regression equation,the core driving factors of social and economic factors are GDP,total retail sales of social consumer goods,investment in fixed assets per capita and housing area per capita.(5)The change characteristics of urban construction land in Changsha is affected by the comprehensive effect of economic driving force,policy regulating force,natural system and social driving force.Among them,economic driving force is fundamental,policy regulating force is guarantee,natural system is basis and social driving force is catalyst.Different driving factors in different periods lead to the differences in the scale,layout and form of construction land in Changsha.From 1990 to 2000,it was mainly affected by urbanization,"one point,one line" strategy,park construction,transportation infrastructure construction,etc.From 2000 to 2010,it was mainly affected by the Central China's Rise Strategy,the relocation of administrative center and urban planning,etc.From 2010 to 2017,it was mainly affected by the integrated construction of Changsha-ZhuzhouXiangtan urban agglomerations,the construction of two types of society in Changsha-Zhuzhou-Xiangtan urban agglomeration,urban transportation construction,and urban residents' pursuit of quality of life.