Research On Regional Ecological Security Pattern Based On Supply-Demand Balance And Circuit Theory

Ecological security is a prerequisite for achieving high-quality regional development.Building an ecological security pattern is one of the ways to maintain the regional ecological bottom line and optimize the allocation of spatial resources.Under the background of "double circulation",urban agglomeration has gradually become the main spatial carrier to participate in international competition and achieve regional high-quality development.Optimizing the ecological security pattern is of great practical significance to promote the improvement of ecological quality and sustainable environmental improvement of urban agglomeration.At present,the research on regional ecological security pattern in China mostly carries out connectivity identification and ecological supply evaluation from the perspective of spatial form,but there is relatively little analysis on the level of ecological supply and demand and its spatial distribution at the scale of urban agglomeration;In recent years,in the evaluation of spatial connectivity,circuit theory has been gradually favored because it can better simulate the characteristics of ecological processes,and its application to large spatial scale research is not enough.Taking Chang-Zhu-Tan "3+5" Urban Agglomeration as the research object,this paper selects the types of ecosystem services closely related to biodiversity protection and human well-being,uses the model method to analyze their supply and demand level and spatial distribution characteristics,and combines the circuit theory spatial connectivity model to comprehensively evaluate the regional ecological security and formulate differentiated optimization strategies,It provides a reference for the spatial development strategy and land spatial planning of Chang-Zhu-Tan "3+5" Urban Agglomeration.The main conclusions are as follows:1)106 ecological sources,193 ecological corridors and 112 potential ecological corridors are identified within the scope of the study,involving land types such as forest land,grassland,pit and beach.Large water bodies have the strongest obstruction effect on ecosystem services,and there is no high overlap between nature reserves and ecological sources in space;2)The ecological pinch area is not necessarily the ecological protection area in the traditional understanding.The obstacle point is the key part affecting the regional connectivity.The elimination of the obstacle point is helpful to open up the potential ecological corridor,and the type of underlying surface affects the difficulty of eliminating the obstacle point.3)The overall ecological security level of Chang-Zhu-Tan "3+5" Urban Agglomeration is high,with95.1% of the areas in the medium-high ecological security level.From the perspective of level evaluation,the regions with oversupply and supplydemand balance account for 90.8%.From the perspective of spatial analysis,the proportion of areas in urgent need of ecological restoration measures is only 7.0%.Taking urban agglomeration as the spatial scale,this paper integrates the two perspectives of horizontal evaluation and spatial analysis.By promoting the balance between supply and demand of regional ecosystem services and improving regional connectivity,this paper constructs a regional ecological security pattern aimed at protecting biodiversity and human well-being,which is a useful supplement to the research on the construction of traditional regional ecological security pattern.Also,the study area showed a higher average ecological safety level in the southeast than in the northwest.