Spatial-Temporal Characteristics And Influencing Factors Of Urban Construction Land Expansion In Chongqing

Urban construction land is the most important carrier of social and economic activities.Scientific development,rational utilization and orderly management of urban construction land are the major strategic tasks of accelerating the modernization of spatial governance system and enhancing the capacity of spatial governance in China,and is also an important breakthrough for promoting regional coordinated development from the land supply side.Since the reform and opening up,along with the rapid development of social economy,industrialization and urbanization,the land use in China has also undergone dramatic changes.The rapid expansion of urban construction land has become the focus of current government departments and academia.It is of great practical significance to understand the direction of land use development and promote the sustainable development of urban economy,society and environment by deeply analyzing the process,characteristics and trends of urban construction land expansion,the influencing factors and its spatial heterogeneity of urban construction land expansion.Based on scarcity theory of land resource,intensive land use theory,location theory and externality theory,this study analyzed the spatial and temporal evolution characteristics of the expansion of urban construction land in Chongqing from 2001 to 2017 from expansion speed and expansion intensity two dimensions to clarify the expansion trend and development direction of urban construction land in Chongqing.The population elasticity index and economic elasticity index of urban construction land expansion was applied to reveal the relationship between urban construction land expansion and population growth,urban construction land expansion and economic growth in Chongqing to provide scientific basis for coordinating population urbanization and land urbanization in Chongqing.Selecting indicators from the perspective of social and economic development,this paper analysised the influencing factors and its spatial heterogeneity of urban construction land expansion in Chongqing from 2001 to 2017 by using grey relational analysis method,which provides a scientific basis for formulating land supply policy according to local conditions.The main conclusions are as follows:(1)From the perspective of time series variation characteristics,the expansion speed of urban construction land in Chongqing during the study period experienced an “M” shaped change process of “rise-down-rise-down”.The population elasticity index and economic elasticity index of urban construction land expansion were similar to the trend of urban construction land expansion in time series.The intensity of urban construction land expansion had shown a trend of increasing first and then decreasing in terms of time series changes.The phase transition characteristics of urban construction land expansion in the city are closely related to regional development policies,land management policies,and changes in regional economic growth.(2)From the perspective of spatial characteristics,the spatial difference of urban construction land expansion in Chongqing was significant,the spatial difference of expansion speed was gradually decreasing,and the spatial correlation was not obvious.The population elasticity index had strong correlation in spatial distribution,and the spatial agglomeration characteristics were obvious;the spatial difference of economic elasticity index was significant,but the spatial correlation was weak,and the spatial agglomeration characteristics were not obvious.The spatial difference of expansion intensity was obvious,and the overall distribution pattern was the largest in the main urban area,followed by the surrounding areas and counties around the main urban area,and the smallest was in southeastern and northeastern Chongqing,which was consistent with the pattern of regional economic development and urbanization in Chongqing.(3)There was a strong correlation between urban construction land expansion and socio-economic development in Chongqing.On the whole,the total retail sales of social consumer goods,GDP per capita and output value of secondary and tertiary industries were more closely related to the expansion of urban construction land in Chongqing,which are the main factors affecting the expansion of urban construction land while industrial restructuring,regional traffic conditions and the total resident population had relatively low impact on the expansion of urban construction land.The expansion speed of urban construction land was mainly affected by per capita GDP,social fixed assets investment,urban population and other factors.The expansion intensity was mainly affected by the total retail sales of social consumer goods,per capita GDP,nonagricultural output value and other factors.(4)The influencing factors of urban construction land expansion in Chongqing had spatial heterogeneity.Generally speaking,the results of the impact of various factors on the speed of urban construction land expansion in districts and counties were in good agreement with those at the city level,but there were also differences.The analysis results based on the correlation degree of influencing factors at the city level were not entirely suitable for the specific situation of districts and counties.The correlation degree between urban construction land expansion and its influencing factors in different districts and counties had obvious spatial differences.It is necessary to adjust measures according to local conditions when formulating strategies to promote the coordination between urban construction land expansion and socio-economic development.