Study On The Optimization Of Territorial Spatial Pattern Based On The Integration Of "Double Evaluation"

Since the 21 st century,with the development of global urbanization to an unprecedented height,the conflict between human development needs for urban construction and agricultural production and the maintenance of the service functions of terrestrial ecosystems has continuously expanded within the limited land space.In this context,the United Nations and many international research organizations have successively launched major scientific plans to cope with global environmental changes and seek sustainable development.The feedback between human activities and the resource-environmental effects has risen to global hot issues.As the process of restructuring China’s territorial spatial pattern accelerates,the increasingly serious conflicts between human-land relations and the sustainable development goals have gradually become more prominent.Against the background of the construction of an ecological civilization system and the goal of "Beautiful China",it has become a major issue of concern to the Chinese government to build a spatial planning system with national land spatial planning as the core and optimize the national land spatial development and protection pattern."Double Evaluation" is an important means to clarify the environmental endowment of land and space resources,and to identify the risks and development potential of land and space.It is the scientific foundation for the construction of land and space strategic pattern.As the "Double Evaluation" guidebook officially released by the Ministry of Natural Resources,the basic and guiding role in the preparation of territorial space planning and the effects applied to the optimization of territorial spatial pattern will be more prominent.Therefore,carrying out research on the optimization of land spatial pattern based on the integration of "Double Evaluation",exploring the logical connotation and practical path from the resource-environmental background assessment to the identification and zoning optimization of land space leading functions can provide theory foundation and technical support for land space functional zoning and use control.It also has strong practical significance in the delineation of "three areas and three lines",the formulation of regional development strategies,the refined management of land and space,and the implementation of planning and implementation.Jiangsu Province is located in a major strategic intersection zone of the country.At the same time,high-intensity land space development is also facing problems such as insufficient expansion space and increased resource and environmental constraints.Scale conflicts,functional conflicts and spatial conflicts between social and economic activities and the natural environment are becoming increasingly prominent.Under the realistic background of the construction of the spatial planning system,how to construct an orderly land and space development and protection pattern has become a key issue that is unavoidable in the sustainable development and ecological civilization construction of Jiangsu Province.Therefore,based on the systematic review of the research results of domestic and foreign resource-environmental carrying capacity,land space suitability and land space pattern optimization,this paper attempts to build the theoretical framework and model of land space optimization zoning based on the integration of "Double Evaluation" by combing related concepts and theoretical foundations.Taking Jiangsu Province as an empirical research area,based on the analysis of the characteristics of its land spatial pattern and evolution law,the characteristics of the conflict between human and land are analyzed from the two dimensions of time and space,and then resource-environmental factors is identified in the process of its land space development.Based on the "rigid constraint-elastic constraint" and "populationland" perspectives,the scale of land and space development that can be carried under the resourceenvironmental constraints of Jiangsu Province is calculated,and then the regional population carrying capacity and construction land bearing level is comprehensively analyzed based on single factor evaluation.Then the paper carries out urban construction,agricultural production and ecological protection suitability evaluation,and based on the land space optimization zoning plan,integrates evaluation results and urban space carrying level,and finally obtains the Jiangsu province land space function zoning optimization plan and divides different types of land space,such as urban,agricultural and ecological space.Dividing Jiangsu Province into six types of leading functional areas at the district and county scale,the paper further proposes strategies for the development and protection of national land space in various regions,and compares with the results of Major Function Oriented Zoning.The results show that:(1)Under the framework of the human-land relationship regional system,human production and living activities and their resource-environmental effects can be explained by the mutual feedback mechanism between the resource-environmental carrying capacity and the land space suitability.Under certain goals,the scale pattern and spatial pattern of the leading functional areas based on the integration of "Double Evaluation" together constitute the land space optimization pattern.The land space optimization zoning plan can be formed by integrating the assessment of resource-environmental carrying capacity of single factor bearing scale and grade and integrating the land space suitability evaluation of each single function,introducing the urban space bearing grade and the selection function of land space leading function under the constraints of ecosystem service functions.(2)The constraints of resource and environment on the population carrying capacity of Jiangsu Province show regional and structural differences.Among them,environmental factors are strongly restrictive to southern and central Jiangsu,while northern Jiangsu is mainly constrained by the total amount of water resources;Under carbon peak conditions,the province’s energy carrying capacity faces certain risks.Ecosystems in different regions have different flexibility for expansion of construction land.As ecosystem functions continue to improve,the focus of the province ’s exploitable space shifts from the Jianghuai Ecological Economic Zone and the Xuzhou urban agglomeration to the urban agglomeration along the Yangtze River.The lowvalue areas are always located in cities along the Taihu Lake;from the perspective of bearing level,the low-value areas are mainly located in the cities of southern Jiangsu and the municipal jurisdictions of Xuzhou and Nantong.(3)The proportion of suitable and less suitable grade areas of urban construction,agricultural production and ecological protection is 36.9%,69.6%,27.2%,and the proportion of unsuitable grades is 63.1%,30.4%,72.8%;after optimization,the area of urban space,agricultural space and ecological space is 28005.50km2,48315.91km2 and 28897.71km2,accounting for 26.62%,45.92% and 27.46% of the land area.The optimized construction area and regulated construction area account for 14.34% and 12.28%,concentrated production areas and optimized production areas account for 15.85% and 30.07%,and strict protection areas and general protection areas account for 9.29% and 18.18%,respectively.(4)By identifying the combined distribution characteristics of different leading functions in districts and counties scale,the province is divided into urban single dominant type,agricultural single dominant type,urban-agricultural dual dominant type,urban-ecological dual dominant type,agricultural-ecological dual dominant type and urban-agricultural-ecological type.Combined with the conflicts between human-land relations and functional positioning of each area,targeted zoning optimization strategies are proposed in terms of spatial layout,scale control and structural optimization.This paper further refines the division of dominant function of Major Function Oriented Zoning at the district and county scales,which helps the implementation of top-down spatial control policies.