Research On The Optimization Of Geographical Spatial Pattern Of Urban Agglomeration In The Middle Reaches Of The Yangtze River Base On The Production-Living-Ecological Function

The optimization of development patterns of geographical space is an important measure to realize construction of ecological civilization in China,which as a major strategic issue is intimately related to the sustainable development of regional economy and society.In the period of rapid development of industrialization and urbanization in China,as the key carrier of industry development and population agglomeration,problems such as unbalanced space development as well as disorderly utilization in the utilization of the geographical space are emerged in the urban agglomeration geographical space.The regional coordinated developments and ecological security pattern encounter severe challenges.As such,how to achieve the optimization of geographical space,scientific arrangement of space development order and efficient use of space resources,has attracted considerable attention in the coordinated development of regional economy and society in the new situation.As clearly addressed in the Eighteenth National Congress of the Communist Party of China,it needs to ensure intensive and efficient use of the space for production,provide the living space more livable and proper in size,to present an unspoiled and beautiful ecological space,and to run a rational distribution and development of geographical space.The critical way to promote the balanced and coordinated utilization of regional space is to optimize the spatial patterns of production-living-ecological space.Located in the middle part of China,the urban agglomeration of the middle reaches of the Yangtze River is a superior large urban agglomeration formed by the Wuhan Urban Agglomeration,the Urban Agglomeration around Changsha-Zhuzhou-Xiangtan and the urban agglomeration around the Poyang Lake,which is not only an important support to lead the rise of central part in China,but also an important growth pole for the development of the Yangtze River Economic Belt.Along with the rapid development of industrialization,urbanization and integration of urban and rural areas in the middle reaches of the Yangtze River,problems such as disorder of spatial development,and the deterioration of the ecological environment are becoming increasingly prominent.In particular,how to locate the different spatial functions of urban agglomerations accurately,and construct the spatial development model reasonably,has become an urgent problem to be solved in the sustainable development.Under this context,the paper focuses on the geographical space of the urban agglomeration in the middle reaches of the Yangtze River,and carries out the relevant research on the geographical space of the urban agglomeration step by step under the logic line of “system characteristics-dynamical mechanism-structure evolution-function identity-spatial optimization-pattern reconstruction” from the perspective of the production-living-ecological function.First,on the basis of addressing the connotation of production-living-ecological function and space,this paper tries to reveal inter-relationships among production-living-ecological function systems of geographical space under the theory of systematical science,in addition to the dynamic mechanism of the evolution of functional system.Second,taking the production-living-ecological function as the research angle,the spatial and temporal evolution laws of the spatial structure of urban agglomeration in the middle reaches of the Yangtze River are discussed from two aspects of the quantitative and the landscape structure.By evaluating the functional level of the urban agglomeration,the distribution pattern attributes of spatial function are investigated from two aspects of spatial heterogeneity and spatial correlation.On the basis of the above,the paper uses the normalized revealed comparative advantage index to distinguish distribution pattern of the superiority function of the urban agglomeration space.Moreover,the method of spatial clustering is adopted to gradually adjust the isolated and irrational units,so as to form the optimization scheme of the geographical space in urban agglomeration in the middle reaches of the Yangtze River.In order to achieve the target of optimizing geographical space,this study starts with the development of industrial,the pattern of urbanization and the layout of ecological security,then puts forward the concrete path of spatial development pattern of urban agglomeration in the middle reaches of the Yangtze River by using the theory of spatial structure.The main research contents and conclusions are as follows:(1)By using the theory of system science,the study constructs the framework of system interaction and operation mechanism of production-living-ecological functional systems in urban agglomeration,and proposes that self-organization mechanism,competition and coordination mechanism,subject demand and dynamic role are the motive forces of system evolution.By using the theory of system science,this paper analyses the characteristics of production-living-ecological functional systems,as well as the inter-relationship among them,and that the production function is the dynamic evolution of the functional system,living function is the link between the production-living-ecological function,ecological function is the stable operation of the system can be guaranteed;the production-living-ecological functional system is a self-organizing system with the characteristics of integrity and openness,dissipative structure,complexity and uncertainty.On the basis of that,this study uses the theory of self-organization and synergetic to reveal the self-organization mechanism,competition and coordination mechanism,subject demand and initiative,which together form the driving mechanism of the evolution of the functional system.(2)The structure of geographical space in urban agglomeration in the middle reaches of the Yangtze River has the regularity in spatial type transformation,spatial pattern change and terrain gradient distribution.The level of landscape agglomeration in geographical space of urban agglomeration shows a downward trend,and the degree of fragmentation is progressively higher.(1)The area of agricultural production space and forest ecological space accounts for more than 80% of the total area.The mutual transformation relationship between the spatial types is mainly the transfer out of agricultural production space and woodland ecological space,and the transfer in of industrial and mining production space and urban living space.The ecological space area of forest land is decreasing obviously,which is changed into industrial and mining production space and urban living space.(2)Agricultural production space,industrial production space,living space,water and other ecological space are mainly distributed in low relief gradient of the low altitude,low terrain gradient and flat terrain undulation.Furthermore,spatial distribution of the forest ecological spatial and grassland ecological has the main advantage in the middle and high level terrain gradient of the high elevation and steep slope and the fluctuation.(3)At the patch level,the number of patches in agriculture,production and rural life spot was the most,showing an increasing trend year by year,and from the view of landscape scale,the agricultural production landscape and forest ecological landscape are the main landscape of urban agglomeration,the level of landscape equalization and diversification gradually increased,the aggregation degree and connectivity decreased gradually,non subject landscape controlling force of the geographical space showed an upward trend.(3)Characteristics of spatial function in the urban agglomeration are presented through the evaluation of the spatial functional level of urban agglomeration in the middle reaches of the Yangtze River: From the perspective of spatial heterogeneity,the spatial distribution of different functions shows a certain degree of differentiation;from the point of view of spatial correlation,there is obvious spatial correlation among different types of functions.Analyzed from the view of spatial heterogeneity,zones with high value of agricultural production are distributed in Jianghan Plain,Dongting Lake plain and Poyang Lake plain.Central city of Wuhan and Changsha have the highest level of industrial production function.Wuhan Urban Agglomeration is connected with Yichang city and Xiangyang city forming a contiguous pattern,while the Agglomeration around Chang-Zhu-Tan Urban grows outwards from the urban units of the core layer in the spatial pattern.Most units with high living functions are those urban units of prefecture level cities and county-level cities.Wuhan Urban Agglomeration is connected with cities in northwest of Hubei Province,forming a zonal distribution pattern.The urban units of Chang-Zhu-Tan Urban Agglomeration together with the county units at the junction of Hunan province and Jiangxi Province form a continuous development pattern.The high value area of ecological function is located in the mountainous areas of West Hubei,Mufu-Mountains,Huaiyu-Mountains,Dongting Lake and Poyang Lake,presenting a zonal distribution in space.From the results of spatial correlation analysis,the production-living-ecological function are characterized by significant spatial agglomeration through the global autocorrelation and local autocorrelation test,while strong differences among clustering patterns of different functions.(4)To achieve the goal of optimizing the geographical space of the urban agglomeration,the scheme of urban agglomeration in the middle reaches of the Yangtze River establishes nine zones as the primary functional zone and thirty-nine zones as the secondary functional zone by way of combining quantitative evaluation and qualitative adjustment.According to the result of comparative advantage function evaluation of urban agglomeration,in conjunction with natural substrate,spatial structure and function distribution pattern,industry and town development planning,nine primary zones are revealed after adjusting the independent units of the advantage function area step by step according to the principle of the regional consistency,conjugation and morphological similarity:ecological functional zone,agricultural production functional zone,agricultural production-ecological function zone,agricultural-industrial production functional zone,life-ecological function zone,agricultural production-living functional zone,industrial production-living functional zone,industrial production-ecological function zone,agricultural and industrial production-living functional zone.On this basis,function zones of the first level are divided into thirty-nine secondary functional zones,and hence establishing the land space optimization scheme of urban agglomeration in the middle reaches of the Yangtze River by the natural partition and zoning principles.(5)In order to ensure the implementation effect of the optimization program of the geographical space,there are various development patterns that need to be constructed including the agricultural production base,the industrial cluster and the development axis belt,the town group and the development corridor,the ecological conservation area and the ecological corridor.(1)Agricultural production base is adopted as the development model to divide the agricultural production space into eight agricultural production bases according to the advantages of different agricultural products.On one hand,for the industrial production space,seven industrial clusters and five industrial development axes are designed by the application of the development mode “Industrial cluster and industrial development axis”.Spatially,the development pattern of the “three vertical axes and two horizontal axes” model will be formed.On the other hand,for the tourism industrial cluster,five tourism industrial clusters and three tourism industry development axes are constructed.Correspondingly,“a vertical axis,two horizontal axes” development pattern in the space is formed.(2)By using the development model of “Core-group-corridor”,the living space is divided into sixteen groups of towns,and six urban development corridor are built,which result in the formation of “three horizontal axes and three vertical axes” development pattern in space.(3)The ecological space is constructed as a three-dimensional network pattern in the space under the layout model of “ecological conservation area and corridor”,which constitutes five ecological conservation areas and ten ecological corridors.