Spatial-Temporal Features And Influencing Factors Of Difference In Urban Land Development Intensity In Six Provinces And One City Of The Middle And Lower Reaches Of The Yangtze River

Reasonable urban land development intensity is the basic guarantee for realizing regional social and economic development,welfare improvement and ecological environment improvement.However,the intensity of urban land development with immoderate will deplete the overall structure of the urban land-use system,which will lead to structural disorder and functional degradation of the land-use system as a whole,and ultimately hinder the sustainable and healthy development of the city’s social economy.In order to reasonably regulate the intensity of urban land development,this paper firstly uses nuclear density estimation and exploratory spatial data analysis methods to explore the spatial and temporal characteristics of urban land development intensity differences between 2000-2016 cities in the six provinces and one city above the middle and lower reaches of the Yangtze River from time and space;secondly,using spatial econometric models to explore the influencing factors of urban land development intensity differences;finally,combined with the spatial and temporal characteristics and influencing factors of urban land development intensity in the six provinces and one city of the middle and lower reaches of the Yangtze River,proposing the targeted urban land development intensity optimization path and countermeasures.The main findings are as follows:(1)During the study period,the land development intensity of the cities above the prefecture level in the middle and lower reaches of the Yangtze River showed an overall upward trend.It generally presents the circle structure with weakening of radiation to surrounding cities centered on Shanghai,Nanjing,Hangzhou,Hefei,Wuhan,Changsha and Nanchang.From the perspective of time series evolution,the results of nuclear density curve show that the land development intensity of the cities above the prefecture level in the middle and lower reaches of the Yangtze River shows a volatility growth trend,and the difference in land development intensity between different cities shows an expanding trend and multi-polarization phenomenon.From the perspective of spatial evolution,there is a significant positive spatial autocorrelation in the land development intensity of the cities above the prefecture level in the middle and lower reaches of the Yangtze River,and there is agglomeration in the spatial distribution;the spatial agglomeration form is divided into four types:"high-high" agglomeration type,"high-low" polarization type,"low-high" collapse type,and "low-low" homogeneous type,and the specific distribution of each type of area is different;the spatial distribution of urban land development intensity cold hot spots have relative stability and exhibit strong spatial agglomeration characteristics,showing the distribution pattern of "hot spots—sub-heat—sub-cold—cold spots",the distribution state of different cold hot spot types has obvious differences.(2)The difference in land development intensity between prefecture-level cities and above in the middle and lower reaches of the Yangtze River is affected by the level of economic development,industrial structure,population size,urbanization development level,land resource endowment,and policy support.In terms of economic development level,the gross domestic product(GDP)has a significant positive effect on the difference in land development intensity between the six provinces and one city in the middle and lower reaches of the Yangtze River;in terms of industrial structure level,the output value of the tertiary industry accounts for the proportion of the output value of the secondary industry(TSP),which has a certain negative effect on the difference in urban land development intensity;in terms of population size,urban resident population(URP)has a significant positive effect on urban land development intensity difference;in terms of urbanization development level,the urbanization rate(UR)has a certain positive effect on the difference of urban land development intensity;in terms of land resource endowment,urban land area(ULA)has a certain negative effect on the difference of urban land development intensity;In respect,the city administrative level(CAL)has a certain positive effect on the difference in urban land development intensity.(3)According to the current reality,difference pattern and influencing factors of urban land development intensity differences in the six provinces and above in the middle and lower reaches of the Yangtze River,cities in the six provinces and one city of the middle and lower reaches of the Yangtze River can start from three levels in the future:"Strictly control the scale of urban incremental land and deepen the potential of urban stock land development","Removing old kinetic energy,stimulating new kinetic energy,and promoting land intensive use with new and old kinetic energy conversion","Development of differentiated land development intensity control mechanisms based on local conditions".Optimize the land development intensity of urban areas above the six provinces and one city in the middle and lower reaches of the Yangtze River,and promote the efficient coupling of urban land development intensity and social development in the region.