Study On The Construction Of Ecological Security Pattern In Water Network Area In Southern Jiangsu

As China enters a new era of construction and development,the rapid development of urbanisation has led to the emergence of regional ecological and environmental problems,and the construction of an ecological security pattern is a necessary guarantee for regional ecological construction.Located in the Taihu Lake basin,the southern Jiangsu region has a superior ecological environment and a distinctive water network,but with the accelerated urbanisation of the region,the contradiction between regional economic construction and ecological development is becoming increasingly significant.Based on the analysis of multisource data to identify ecological sources,corridors and nodes that need to be protected and constructed,it is important to build and optimise the ecological security pattern of the water network region to ensure ecological security and stability in the water network region and to promote the balanced development of the regional economy and ecology.This study aims to protect the ecosystem service function and optimise the landscape connectivity in the water network area,and discusses the construction of ecological security patterns in the water network area according to the idea of "ecological source site identification-ecological resistance surface establishment-ecological corridor extraction-ecological node identification".The method of constructing ecological safety patterns in the water network is discussed in the context of "ecological source site identification-ecological resistance surface establishment-ecological corridor extraction-ecological node identification".The study combines the InVEST model and MSPA analysis to evaluate the functional importance and structural importance of Kunshan City,and to identify the ecological source sites by integrating the evaluation results;to establish the ecological resistance surface with the MCR model;to extract the ecological corridors and ecological nodes in the area by combining the circuit theory;to construct the ecological safety pattern of the water network area on this basis,and to propose strategies and suggestions for optimising the ecological safety pattern of Kunshan City.The main research contents of the thesis are as follows.(1)In the identification of ecological source sites in the water network area,the InVEST model and MSPA analysis are combined to analyse both structural importance and functional importance,which can make the identification results more comprehensive and scientific.For the identification of ecological corridors and nodes,the combination of the MCR model and circuit theory allows for the identification of critical paths in the region while clearly reflecting all possibilities for ecological circulation.Combining the above methods can,to a certain extent,improve the scientific accuracy of the identification of ecological source sites,corridors and ecological nodes,and can also provide new ideas for the construction of ecological safety patterns in water network areas.(2)Ecological source areas are the source of ecological circulation and the core areas of ecological security patterns.Based on the ecological characteristics of Kunshan City,the study combined the ecological problems of the study area and,with the help of the InVEST model,selected four indicators of biodiversity service,soil conservation,water content and carbon storage to evaluate the functional importance of Kunshan City;with the help of MSPA analysis,selected two indicators of spatial pattern and landscape connectivity to evaluate the structural importance of Kunshan City.The results were combined to identify24 ecological source sites.The ecological source sites in Kunshan are mainly located in the south and northwest of the region,and the land use type is mainly lakes.(3)Ecological corridors are important bridges between ecological flows and ecological nodes are key localities that play an important role in ecological processes.The extraction of ecological corridors and the identification of ecological nodes are important for the construction and optimisation of regional ecological safety patterns.The MCR model was used to establish the ecological resistance surface of Kunshan City,and combined with circuit theory to identify ecological corridors and ecological nodes in the study area.A total of 46 optimal corridors were identified,with the optimal corridors in the north being longer and more scattered on average;the ecological pinch points were mostly distributed in the central part of Kunshan in the form of strips,and the land use was mainly woodland and water;there were 33 ecological obstacle points in Kunshan,and the land use type was mainly construction land,with a small amount of arable land.(4)Integrating the identification results of each landscape component,the ecological security pattern of Kunshan City was constructed,and corresponding strategies and suggestions were put forward for the optimisation of the ecological security pattern of Kunshan City in terms of strict control of important ecological source sites and flexible maintenance of general ecological source sites;protection and utilisation of optimal corridors and development and control of potential ecological corridors;maintenance and management of ecological pinch points and improvement and optimisation of ecological obstacle sites;delineation of ecological protection zones and strengthening of regional macro-control.Strategies and recommendations.