Delineation Of The Development Boundary Of The Central Urban Area Of The County Area

The process of urbanization is an important manifestation of national economic and social development since the reform and opening up.A large number of people have entered the cities from the countryside,which has caused the urban population to continue to grow,and the urban construction land continues to expand.Excessive urbanization has caused extensive spread of urban construction land,the utility of land has not been improved,and land resources have been wasted on a large scale.At the same time,the blind expansion of urban construction land has caused cultivated land to be squeezed,and the proportion of cultivated land has been declining,making it difficult to guarantee food security;Ecological land has been destroyed and the carrying capacity of the ecological environment has declined.Therefore,it is necessary to guide the orderly expansion of urban space by delimiting the boundaries of urban development,improve the utility of future urban construction land,and prevent urban construction from bringing about ecological and food security problems.Taking Lingqiu County as the research area,this paper explores the expansion mechanism of urban construction land from two aspects:the quantitative and morphological characteristics of urban expansion;Use geographic detectors to quantitatively analyze the driving factors of urban expansion;Use mathematical methods to determine the scale of future urban expansion;For the purpose of ecological protection and cultivated land protection,conduct ecological protection importance evaluation and urban construction suitability evaluation,and identify urban construction restricted areas;Based on the FLUS model to simulate the land use change from 2018 to 2030,and delineate the urban development boundary line,and put forward practical suggestions for the future urban development of Lingqiu County.The main conclusions of the study are as follows:(1)From 1980 to 2018,the area of built-up land in the central urban area continued to grow,showing a pattern of rapid first and then slower throughout the study period.The spatial form gradually became more regular,and the urban land center of gravity moved significantly to the north.According to the analysis of the influence of the geographic detector on the driving factors,the 8 factors that have a greater influence on the expansion of the central city are:distance from town center,distance from general hospital,road network density,distance from middle school,distance from elementary school,distance from scenic spots,distance from transportation hub,distance from cultivated land.(2)According to forecasts,by 2030,Lingqiu County has a resident population of 254,700 and an urban resident population of 123,000.The urbanization rate will reach 48.29%,and the urban land scale will be 16.67km2.Through the spatial constraint analysis of urban land use in the central city,the allowable construction area and non-construction area of the town are obtained through integration.Among them,the total area of permitted construction area is 116.60 km2,accounting for 52.51%of the total area,and the total area of non-construction area is 105.45 km2,accounting for 47.49%of the total area.(3)The FLUS model is used to construct an urban construction land expansion model,and the overall accuracy of the model accuracy is 0.8906,and the Kappa coefficient is 0.8408.The overall accuracy and Kappa coefficient meet the consistency requirements.Set model parameters,the cost matrix is formed with reference to the conversion matrix between various land use types within the scope of Wuling Town from 1980 to 2018,combined with constraints and expert suggestions.The neighborhood weight uses the dimensionless value X*of the total area change rate of each land type,the X*value of urban land is 1,the X*value of other construction land is 0.1248,and the value of X*of other land is lower than 0.01,the X*value of cultivated land is 0.The target number of pixels only set three types of land:water area and tidal flat,urban land and other construction land,water area and tidal flat 5434,urban land 18522,and other construction land 14003.(4)The following "three lines" coordination scenario delineated urban land as a central city Lingqiu 2030 town development boundary line,the total area included within the boundaries 16.67km2,which in 2018 built area 11.81km2,from 2018 to 2030 urban growth construction land is 4.86km2.This boundary is an "elastic boundary" relative to the urban space.It can be dynamically adjusted in response to the uncertainty of the future urban development of Lingqiu County,but the premise is that the total land scale included in the development boundary remains unchanged during the planning period and must be within carried out inside the town space.