Research On Characteristics,Dynamic Mechanism And Optimization Strategies Of Spatial Development Of Metropolitan Region

Metropolitan region is the inevitable stage of regional urbanization development,and is also the basic spatial unit for cities to participate in international competition in the era of globalization and information.To explore the law and optimization strategies of spatial development is one of the core topics of metropolitan region construction.This study takes three metropolitan regions in the middle reaches of the Yangtze River as the empirical research objects.Based on the temporal logic of "past-present-future",this paper firstly reveals the characteristics of spatiotemporal evolution process and current spatial structure,then explores the dynamic mechanism of spatial development,and finally puts forward the optimization strategies of spatial development.The first part focuses on the spatiotemporal characteristics of metropolitan region evolution.Based on the comprehensive analysis method of "population-economy-space",it is shown that the population and economic development generally goes through three stages,namely accumulating period,core agglomerating period and core spillover period.The spatial evolution also undergoes three stages in turn,the stage of gathering growth of the core circle,the stage of continually expansion to the middle circle with rapid dot growth in the peripheral circle,and the stage of axial expansion from core to peripheral.The second part reveals the characteristics of spatial structure of metropolitan regions from the perspective of urban functional relationship.Based on the gravity model and the business contact method,this reaserch constructs the gravity connection network and the enterprise association network,and explores the nodes’ hierarchical structure and the associations network pattern by using the Social Network Analysis method.The results show that,the level of functional nodes is obvious,including 4 types,namely control center,entrepot,secondary center and edge node.The network structure is characterized by centripetal agglomeration,vertical hierarchy and "core-edge" differentiation.The third part reveals the characteristics of physical spatial structure of metropolitan regions.This part uses quantitative analysis methods,including regional density function,fractal dimension analysis,the Minimum Cumulative Resistance model and so on.It is found that the metropolitan regions present "single core / multi-core with double-layer nodes" central system structures,"ring+radial" traffic network structures,with ecological space structures characterized by "mountains and rivers across the core,corridor network in the middle,wedge green land from peripheral into the city".The land use pattern is characterized by circle form,centripetalism and axial imbalance.The fourth part focuses on the dynamic mechanism of metropolitan region spatial development.Based on existing theories,this paper constructs the analysis framework of "subject behavior-environmental elements-spatial effect",analyzing the action mode of three types of subject behaviors and four types of environmental elements on the spatial system and their mutual coupling mechanism.It is found that the subject behaviors are the key perspective to understand the representational characteristics of the spatial system,and government subject behaviors play a decisive role in the spatial development of the metropolitan regions.The fifth part puts forward the optimization strategies of metropolitan region spatial development.Based on the previous research,the key problems of spatial development are put forward,the spatial development trend is also predicted.Then,it discusses the spatial structure optimization modes and its common characteristics.Furthermore,it puts forward the optimization path of spatial development,including guiding subjects’ behaviors,improving the role of factors,rational organization of urban functional network and optimization of physical spatial structure.Through the above work on the spatial development characteristics,mechanism and spatial organization optimization strategies of the metropolitan regions,this research enriches the study of meso scale regional spatial organization and innovatively develops the spatial structure theory of metropolitan region.Meanwhile,it has great significance to the practice of spatial planning of metropolitan regions in the current period of territorial spatial governance.