Spatial And Temporal Evolution And Optimization Path Of Land Use Efficiency In Urban Agglomerations

The rule of world economic development tells us that economic agglomeration is the trend of the times,and the future urban agglomeration will become a new geographical unit for countries to participate in global competition.The Chinese government and a large number of scholars actively support the construction of urban agglomerations.The urban agglomerations will give full play to the role of strategic support points and growth poles,and become the most dynamic and potential region in the future urbanization process in China.Against the background of the contradiction between urban land expansion and cultivated land protection,the contradiction between the demand for construction land driven by economic development,the limited scarcity of land resources,and the non-intensive and economical use of stocks in urban areas have forced us to fully Exploring the land use potential of urban agglomeration stocks,so scientifically measuring the temporal and spatial evolution of land use efficiency of urban agglomerations in different stages of development in China and analyzing its optimization path,it is an important reality to improve the level of urban land intensive conservation and utilization and achieve high quality development of urban economy.significance.This paper takes 138 prefecture-level cities in China's eight national-level urban agglomerations as research areas.Based on the evaluation index system of constructing input,expected output and non-expected output,the SBM-Undesirable super-efficiency model based on global reference is 2006-2015.Scientific measurement of land use efficiency in urban areas of the eight major urban agglomerations.Based on the results of urban land use efficiency,the current and temporal evolution rules are studied in detail.At the same time,the spatial difference and spatial correlation of efficiency are analyzed by introducing the Theil index,global and local spatial autocorrelation methods.Finally,based on the resource input and the undesired output redundancy,the relevant suggestions for the efficiency optimization of each urban agglomeration are proposed.Research indicates:(1)In terms of time series changes,the overall urban land use efficiency of the eight major urban agglomerations declined first and then increased,and the overall land use level improved.In terms of efficiency decomposition,pure technical efficiency is lower than scale efficiency for a long time,that is,the allocation level of resource elements in land use does not reach the optimal state,which is the main reason for the low overall efficiency.In terms of urban agglomerations,the land use efficiency of the three major urban agglomerations in the east is relatively high,and it has increased significantly during the inspection period.The five central cities in the central and western regions have low efficiency,and they have risen slowly during the inspection period and even some urban agglomerations have declined.(2)In terms of spatial evolution,the urban land use efficiency of urban agglomerations is “higher in the eastern and lower in the midwest”.The results of the Taier index time series show that the difference between the groups is significantly expanded,that is,the regional imbalance is gradually intensified.In terms of space,from a global perspective,the Moran'I index of the eight major urban agglomerations in 2015 was 0.329,that is,the utilization efficiency of construction land in each city has a certain agglomeration effect in space;in some cases,high-value agglomeration occurs in some areas of the eastern urban agglomeration.The technology spillover effect of urban agglomerations in urban agglomerations has gradually become apparent.The central and western urban agglomerations are mainly characterized by a “centralperipheral” pattern.The core cities of urban agglomerations are still in a stage of rapid development,and urban diffusion effects are low.(3)In terms of the efficiency improvement path,the redundancy of each factor has decreased in different degrees during the inspection period,and the level of land use resource allocation has improved.However,there is still a problem of excessive capital investment and excessive sulfur dioxide emissions in the land use process.The main reason for the use of inefficiency.In 2015,the redundancy of various factors showed the distribution characteristics of “higher in the east and lower in the midwest”and“higher in the big cities and lower in the small”,that is,the phenomenon of factor redundancy is mainly concentrated in the central and western regions or small cities.Therefore,in order to improve the land use efficiency of urban agglomerations,it is necessary to focus on solving the problem of capital over-investment and industrial sulfur dioxide control.At the same time,support for the economic development of the central and western regions or small cities cannot rely on resources to invest heavily,and more support should be given in terms of technology.The economy is of high quality and the level of land intensive conservation is further improved.