The Scale Of Urban Construction Land From The Perspective Of Urban Development Boundary Delimitation

Urban construction land is the main carrier of social and economic activities.After more than 40 years of reform and opening up,China's industrialization and urbanization have developed rapidly and made remarkable achievements.However,the rapid expansion of urban construction land also occupies a large amount of agricultural land and ecological land,which seriously threatens national food security and ecological security,and leads to extensive urban development and low land use efficiency.Therefore,the scientific development and orderly management of urban construction land are closely related to national economy and people's livelihood.After years of exploration and practice,the urban development boundary is considered to be an effective policy tool for urban growth management,and an important means to implement the strategic goal of accelerating the modernization of space governance system and enhancing the capacity of space governance.Predicting urban construction land scale accurately is the most important part in previous urban planning,and the same is true for urban development boundary delimitation.It is related to control effect of the boundary.Based on some theories,such as the theory of land intensive use,the theory of urban development.Multiple linear regression model is used to predict construction land scale in this paper.The specific process is to find out the land scale by predicting the model explanatory variables with the limit state of urbanization,and then propose some control measures.The main conclusions are as follows:(1)From the perspective of urban development boundary delimitation,the scale of urban construction land is the limit scale of urban growth,which can be predicted by the way of "reverse constraint" or "forward growth".The way of "reverse constraint" reverses the scale of urban construction land by determining the insurmountable ecological bottom line,and it is suitable for megacities with rapid population growth and high ecological pressure,or cities with small scale and much ecological restriction.The way of "forward growth" determines the scale of urban construction land according to the needs of urban development,and it is suitable for general cities with a small proportion of ecologically protected areas and a normal population growth rate.(2)Jiangjin district will reach the limit rate of urbanization in 2045.According to the development orientation of Jiangjin,the integration of Jiangjin and Chongqing's urban core areas is inevitable.The limit rate of urbanization in Jiangjin can be judged by the urbanization process of the main urban areas in Chongqing.According to the analysis of the urbanization process and the expansion of urban construction land in the main urban areas,urban construction land will not increase anymore until the urbanization rate rises to 92.5%.According to the prediction result of the Logistic model,Jiangjin will reach the limit rate of urbanization in 2045.(3)From the perspective of urban development boundary delimitation,the limit scale of urban construction land in Jiangjin will be 187.88km2.According to the urban development orientation of Jiangjin and the urbanization process of the main urban areas in Chongqing.Jiangjin will reach the limit rate of urbanization in 2045.The predictive results of the model explanatory variables are as follows: the fixed asset investment of the whole society is about 143.25 billion yuan,the output value of the secondary and tertiary industries is about 146.05 billion yuan,the urban population is about 2.126 million,and the construction land utilization benefit is about 23.373 million yuan per hectare.According to the multiple linear regression equation,the limit scale of urban construction land in Jiangjin will be 187.88km2.