The Spatial Pattern Of Urban Land Gradation And Its Influencing Factors In Hunan Province

In recent years,with the continuous development of economy and society and the rapid progress of urbanization,the scale of urban built-up area is constantly expanding,urban land is increasingly scarce,and the contradiction between people and land is increasingly prominent.Urban land is the embodiment of the overall quality of urban land,reflecting the regional differences among the cities.The gradation of urban land can not only comprehensively give expression to the quality and utilization of urban land,ensure the maintenance and appreciation of state-owned land assets,but also contribute to the healthy development of land market.Under the guidance of the differential rent theory,price theory and location theory,this paper takes the urban land of 29 cities in Hunan province as the research object,using the NPP-VIIRS nighttime light,economic and social data,DEM data and administrative division data,with the help of ArcGIS,SPSS software and other technology,using the multi-factor comprehensive evaluation method,principal component analysis(pca)and cluster analysis method,to systematically analyse the comprehensive quality of the urban land and grade them,and then analyse the spatial distribution characteristics of the urban land in Hunan province.The Geodetector model is used to explore the influence of different factors on different spatial patterns of urban land.The main research conclusions are as follows:(1)The accuracy of built-up areas in Hunan province extracted on the NPP-VIIRS night light image data after correction and statistical information on provincial scale is higher,then establishing the night light index,the correlation coefficients between night light index and urban population,land and economic agglomeration scale are 0.7860,0.8391 and 0.7192,respectively,which showed that there is a good correlation between the night light index in Hunan province and various indexes of urban agglomeration scale,therefore,it is effective as auxiliary to analyze the urban land gradation in Hunan province.(2)On the basis of the regulations for gradation and classification on urban land(GB/T18507-2014),this paper introduces the night light index and supplements some urban infrastructure indicators for communication,communication,education and health which are better reflect of the living standards of modern cities.The evaluation index system of urban land gradation in Hunan province are established from eight aspects including city location,the scale of urban agglomeration,urban infrastructure,urban land input and output level,regional level of economic development,the urban land potential,the urban environment quality,regional comprehensive service ability and so on,and the 29 cities in Hunan province are divided into 6grades.The results show that the gradation of urban land in changsha-zhuzhou-xiangtan region is usually better,and it in west Hunanis generally lower.The spatial pattern of urban land gradation and economic development level are in good agreement,and is closely related to the urban size,the land gradation of prefecture level city is generally higher than that of county-level cities.(3)The geographical detector model is used to analyze quantitatively the influence factors of urban land gradation.The results show that the most important factors affecting the spatial pattern of urban land gradation in Hunan province include the built-up areas,population of permanent residents in city center,real estate development investment,investment in fixed assets and GDP;The subdominant factors are per capita GDP,transportation condition index,and output value of the second and tertiary industries.This paper introduces new NPP-VIIRS nighttime remote sensing data to construct night light index,and improves the urban land gradation index system.The dominant factors of urban land spatial pattern is explored by Geodetector,however,the interaction mechanism between these factors needs to be further explored and revealed.