Research On Spatial Pattern Of Idle Land And Local Environmental Characterization

With the rapid development of China’s urbanization,the crisis and problems are becoming more and more serious while making achievements.The frequent occurrence of idle land is one of the increasingly prominent problems in the process of urbanization.A huge number of idle land has been formed because a large number of construction land is undeveloped or partially developed in China for a long time,which leads to a lot of waste of land resources,it not only disturbs the normal operation of the land market,but also puts great pressure on the land regulatory authorities.The research on idle land considering the differences of spatial distribution and local environmental characteristics makes up for the deficiency of the existing research on the local characterization of idle land,and can provide reference for land spatial planning and land use control.This paper takes Liuyang,one of the three pilot areas of rural land system reform,as an example to investigate all suspected idle land cases in the study area by the end of 2017,and take photos of the surrounding environment of each case with camera.8762 local environmental characteristics of 557 idle land cases in Liuyang City are automatically extracted by using Pycharm as the development tool and Python as the development language,this paper attempts to define the spatial distance and semantic distance to explore the representation relationship between the spatial pattern of idle land and local environment.The main conclusions are as follows:(1)During the study period,there was no obvious change in the time trend of idle land in Liuyang City,but there were a large number of idle land in the process of urbanization,mainly distributed in Yong’an Town,Dongyang Town,Guankou street and Jili street,among which Yong’an town had the largest number of idle land and the largest area;Using Zipf law to analyze the current situation of idle land in Liuyang City,it was found that the area of idle land in township(town,street)conforms to the reasonable state described by Zipf law,and the concentration degree of the number of idle land in township(town,street),the area of idle land for different purposes and the distribution of idle land for different purposes were lower than the expectation of Zipf law.(2)During the study period,the idle land in Liuyang City was analyzed by nuclear density with a bandwidth of 2500 meters,and the analysis results were divided into nine categories according to the natural breakpoint method.It was found that the spatial distribution of the idle land in Liuyang City was mainly concentrated in the urban area(including Jili,huaichuan and Hehua streets)and the towns adjacent to Changsha County(including Yong’an,Dongyang and Beisheng Town,etc).(3)During the study period,the further use of global Moran index and local Moran index of idle land in Liuyang City was verified and analyzed.It was found that the global spatial autocorrelation analysis with township(town,street)as the statistical unit had more significant spatial aggregation in area and quantity than the global spatial autocorrelation analysis with the whole city as the statistical unit.From the perspective of local spatial autocorrelation analysis,the area and quantity of idle land in the townships(towns and streets)of Liuyang City presented "high-high" clustering in Yong’an,Dongyang and Beisheng towns in the west,and "low-high" clustering in Jiaoxi Township in the west of the middle.(4)Based on the analysis of the local environmental characteristics of idle land in Liuyang City,it was found that the number of local environmental characteristics of idle land in different townships(towns,streets)was linearly correlated with the number of idle land in the township.The local environmental characteristics of Yong’an,Dongyang and Beisheng towns in the nuclear density concentration area showed certain similarity,which was mainly manifested in housing,construction,field and mountain.(5)By defining a variety of distances to analyze the spatial pattern of idle land in Liuyang City,it was found that the clustering of idle land based on spatial semantic distance could effectively make up for the shortcomings of spatial clustering and semantic clustering of idle land,and could give consideration to both spatial similarity and semantic similarity to obtain more objective clustering results.