Construction And Optimization Of Water System Ecological Network In Jinan’s Start-up Area For Growth Drivers Transformation Based On SPANs

In recent years,due to issues such as water scarcity,frequent water disasters,and water environmental pollution,water system problems have gradually become important factors limiting the social and economic development of cities.The attention to water system comprehensive improvement has increased continuously,and it has become an important demand for the high-speed development of China’s urban social economy."Four waters and four definites" has become a principle that needs to be well understood and grasped in land spatial planning.The contradiction between rigid constraints on water resources and extensive water use patterns in urban and rural development has become a prominent contradiction that restricts ecological protection and high-quality development in the Yellow River Basin,especially in the downstream areas.Therefore,summarizing the research paradigm of ecological network construction in urban new areas under the constraint of water resources,and then leading the construction of a water-saving society across the entire region,is an exploratory direction for future innovative urban development planning.As an important part of land spatial planning,ecological network construction not only needs to consider the utilization and protection of natural resources such as mountains,rivers,forests,fields,and lakes,but also comprehensively consider the development of social economy and the needs of human activities,and achieve coordinated development of ecological environment and economic development.This article,based on the theoretical and practical research literature related to ecosystem service flows at home and abroad,takes the new and old kinetic energy conversion pilot area in Jinan City as an example.Based on the redivision of watershed boundaries using GIS Pro hydrological analysis tools,it constructs the process and methods of evaluating and simulating the supply and demand of three types of water-regulating ecosystem services,namely,freshwater supply service flow,rainwater regulation service flow,and water quality purification service flow,based on the SPANs model.Firstly,based on the principle of "source-sink-user" of the ecosystem service flow SPANs model,the ontology feature library of service flows is constructed,and the potential supply and benefits of the three types of water-regulating ecosystem service flows,namely freshwater supply service,rainwater regulation service,and water quality purification service,are quantified within the research scope.Further,the actual supply capacity of ecosystem service flows in the research area is evaluated,providing a foundation for the identification of source areas in subsequent ecological network construction.Secondly,starting from the flow process of "supply-flow-demand" of ecosystem service flows,using the SPANs model,spatial flow and flow volume simulation of the three types of water-regulating ecosystem service flows,namely freshwater supply service flow,rainwater regulation service flow,and water quality purification service flow,are conducted,providing a foundation for corridor extraction and node identification in subsequent ecological network construction.Finally,based on GIS Pro software and combining multiple research methods,a research paradigm for exploring the construction of ecological networks from the dimensions of "patternprocess-function" is proposed.This includes identifying structural potential ecological source areas using land use data and MSPA model,identifying functional potential ecological source areas based on actual supply transformation capacity of ecosystem services and MSPA model,extracting comprehensive potential source areas through landscape connectivity analysis,and ultimately obtaining 22 ecological source areas in the study area by combining with ecological red line protected areas.In addition,potential corridors and structurally important corridors are extracted using MCR and gravity model,and ecological flow corridors are identified using SPANs model.The comprehensive distribution map of ecological corridors in the study area is obtained by connecting bridge areas and existing water systems while removing duplicate redundant corridors and connecting some "disconnected" corridors.A total of 61 ecological corridors are identified.Based on the intersection points of ecological corridors,structural ecological nodes of the ecological network are identified,including "barrier points" that reflect the characteristics of structural vulnerability and "junction points" that reflect the importance of functionality,based on circuit theory.The flow nodes with the largest flow capacity in the ecological flow process are identified using SPANs model.After overlaying and removing ecological nodes located in ecological source areas and those close to them,a total of 67 ecological nodes are obtained.Then,based on the importance of ecological structural features,an ecological network framework of "one belt,three axes,six corridors,four cores,eight hubs,and multiple nodes" is constructed,providing reference for the construction and development of the starting area in the next step,and providing a research paradigm for the construction of ecological networks in the context of tight constraints on water resources in the new area of Jinan City.Based on the achievements of the ecological network,strategies for classifying,optimizing,and upgrading the internal ecological network elements in the starting area of the new and old kinetic energy conversion in Jinan City are proposed from three aspects: hierarchical protection of ecological source areas,optimization of ecological corridor connectivity,and improvement and upgrading of ecological nodes.These strategies aim to complement the deficiencies of the planning draft by setting up ecological core areas,increasing ecological corridors and nodes,and other measures.