Analysis Of Ecological Security Pattern In Shanghai Based On The Supply Demand Relationship Of Ecosystem Services

Ecosystem services play an important role in maintaining and improving human well-being and promoting urban sustainable development.With the rapid development of urbanization,the excessive interference of human activities makes the natural ecological space discrete significantly,the urban ecosystem service function continues to degenerate,and the supply capacity of ecosystem services decreases.At the same time,the development of social productivity and the improvement of urban life quality promote the increasing demand for ecosystem services,and the relationship between the supply and demand of ecosystem services Urban environmental problems,such as carbon emission concentration,water shortage and habitat fragmentation,are becoming increasingly prominent,and the risk of urban ecological security is increasing.The existing researches focus on the evaluation of the supply capacity or demand intensity of ecosystem services,but pay less attention to the ecological security pattern from the perspective of supply-demand relationship.Therefore,based on the actual human needs,quantitative evaluation of the supply and demand degree of ecosystem services,revealing the supply-demand relationship and its spatial pattern differences of ecosystem services,and constructing the regional ecological security pattern can provide reference for ecological security System management and rational allocation of resources provide decision support,which is of great significance to the optimization of land space and the healthy development of cities.Taking Shanghai as an example,this paper uses remote sensing interpretation,model simulation and geospatial mapping to identify the spatial-temporal pattern differences of land use in Shanghai from 2000 to 2017,carry out landscape recreation services,oxygen release services,water conservation services and habitat maintenance services evaluation,simulate and analyze the level of supply,demand and supply-demand relationship and their spatial-temporal pattern differences This paper divides the ecological security pattern by using the point analysis tool,and puts forward the optimization and regulation ways of ecological security pattern,which can provide reference for the protection and construction of urban ecological environment in Shanghai.Through this study,the following conclusions are obtained:(1)The land use pattern of Shanghai changed significantly from 2000 to 2017.In 2000,cultivated land was the main type,accounting for 55.44%;in 2017,the proportion of cultivated land decreased to 29.43%,and construction land became the main type,accounting for 36.74%.In recent 20 years,the cultivated land area has decreased significantly,with a decrease of 1962.22 km~2.The construction land area has increased significantly and developed intensively.The landscape fragmentation trend of other land use types is significant,and the risk to urban ecological security has increased significantly.(2)In recent 20 years,the supply level of ecosystem services in Shanghai has declined,while the demand level of ecosystem services has increased significantly.The supply level of oxygen release service,water conservation service and habitat maintenance service decreased by 13%,11%and 25%respectively,while the demand level of oxygen release service and water conservation service increased by more than 60%.The demand of habitat maintenance service and landscape recreation service also showed an upward trend,and the supply-demand relationship of ecosystem service was obviously in a state of short supply;in terms of spatial distribution,the demand level of ecosystem service increased The supply of ecosystem services increased gradually from the city center to the periphery of the city,while the demand of ecosystem services decreased gradually from the city center to the periphery of the city,resulting in the serious dislocation of supply and demand of ecosystem services.(3)From 2000 to 2017,the supply-demand ratio of landscape recreation services,oxygen release services,water conservation services and habitat maintenance services in Shanghai decreased by 0.04,0.08,0.23 and 0.08 respectively,and the imbalance between supply and demand of ecosystem services increased.The spatial pattern of the supply-demand ratio of ecosystem services basically presents the pattern of low in the city center and high in the city edge,which is related to the change of urban ecological spatial pattern.(4)Shanghai’s urban ecological security pattern can be divided into four areas:ecological maintenance area,ecological optimization area,ecological restoration area and ecological conservation area.Combined with Shanghai’s urban master plan(2017-2035),different regions should adopt different zoning optimization strategies to optimize the balance of supply and demand of urban ecosystem services,so as to effectively reduce urban ecological environment risks.However,the types of research on supply and demand of ecosystem services selected in this study are limited,the assessment results need to be further refined,and the results of ecological security pattern are relatively rough,which need to be further studied.