Study On The Evolution And Optimization Of The Spatial Form Of Small And Medium Towns Based On Multi Source Data

The Huaihe River Basin has fertile land and abundant water resources.Since ancient times,it has been an important main grain-producing area in my country,and it is also an area where human activities are very frequent.At present,with the continuous advancement of urbanization and industrialization in my country,the construction space of small and medium-sized cities in the Jianghuai region is rapidly expanding,and the contradictions between urban construction,food security,and ecological security are gradually emerging.The study of the evolution of the spatial form of small and medium-sized cities in the Jianghuai region is crucial to the realization of ecological security.The rational use of urban land and the sustainable economic development under the double red line control of food security and food security have important theoretical and practical significance.Mingguang City is located in the Jianghuai River Basin,with beautiful mountains and rivers.It is a national high-quality rice and rapeseed production area,an important national production base of livestock and poultry products,melons,fruits and vegetables,and an important node town for the integration of the Yangtze River Delta and the integration of Ningxia and Chuzhou.At present,problems such as unclear direction of urban space expansion,extensive urban sprawl,conflict between cultivated land and urban construction,and ecological environment damage are important challenges for the urban development of Mingguang City.In accordance with the research idea of "feature identification-mechanism cognition-classification prediction-comprehensive management and control",based on historical maps and multi-period Landsat remote sensing images,this paper uses methods such as urban morphology and space syntax to explore the two aspects of external form expansion and internal structure evolution.From a perspective,the urban space evolution process of Mingguang City from 1949 to 2020 was sorted out and studied.Combined with the PLUS-CA model,four development scenarios of natural development,ecological security,food security,and planning guidance are set,and the land use change and urban space expansion of the main built-up areas of Mingguang City are simulated in 2035,and the external spatial form,internal spatial structure,and regional coordinated development,and puts forward the optimization strategy and development suggestions of urban spatial form.The results show that:(1)The evolution of urban spatial form in Mingguang City has gone through four stages: start-exploration-growth-acceleration,and the speed and intensity of urban space expansion have experienced a three-stage process of "increase first,then decrease,and then accelerate".The urban development model is gradually changing from a single-center circle-by-layer expansion to a multi-group leap-forward expansion.Urban external space expansion and internal space organization are synergistic,the transfer direction of integrated core,urban space expansion,urban geometric center of gravity transfer,and urban accessible center of gravity transfer are basically the same,and the order of urban space is enhanced under the guidance of the traffic axis.(2)The evolution of urban spatial form in Mingguang City is affected by multiple factors including natural environment,population economy,road traffic and planning policies.Among them,the natural environment is the driving force,providing infrastructure conditions for urban growth,and at the same time restricting urban expansion;the social economy is the driving force,providing support for urban development,attracting a large amount of investment,and promoting the improvement of infrastructure;road traffic is the traction force,providing urban development.Provide guarantee,drive the development of industrial economy,and strengthen the spatial structure;policy planning is the control force,which defines the positioning of urban development,controls the direction of urban development,guides and improves the layout of land use and functions.(3)Multi-scenario prediction of urban space in Mingguang City through the PLUS model.The results show that it is difficult to guide the development of urban space in a compact and intensive direction through restrictive planning elements.It is necessary to combine planning policies,through rigid control and flexible guidance,to support the high-quality expansion of urban space.Based on the results of various simulation scenarios,and on the basis of studying and judging the future spatial expansion trend of Mingguang City,a 41.52km2 urban spatial expansion guiding boundary is delineated,and the spatial expansion mode of "one main body,two wings and multiple clusters" is determined,which will lay a solid foundation for Mingguang City in the future.Space expansion provides certain program guidance and reference.(4)Aiming at the practical problems faced in the development of urban space in Mingguang City,strategies and suggestions for optimizing management and control are put forward from three perspectives: external boundary optimization,internal space,and regional structure optimization.Figure 53 table 36 reference 94...