Urban Green Infrastructure Ecosystem Services Evaluation And Application In Planning And Design Practice

Green infrastructure provides important ecosystem services for the city.Based on their concepts and characteristics,urban green infrastructure ecosystem services can be divided into three categories:provisioning services,regulating and supporting services,and cultural services,including 13 ecoystem service types(water provisioning,agricultural production,runoff mitigation,water purification,carbon sequestration and oxygen releasing,air purification,noise reduction,climate regulation,biodiversity conservation,recreation,aesthetics,scientific research and cultural heritage).This research summarizes the evaluation methods of different ecosystem services provided by urban green infrastructure,including functional value method,equivalent factor method and model evaluation method and discusses the research progress,influencing factors,calculation method and evaluation basis for each kind of ecosystem services.Adaptive management can solve the uncertainties as well as a number of other issues in the practice of urban green infrastructure planning and design.The green infrastructure adaptive management process includes the setting of performance goals,the implementation of site planning and management,the monitoring and evaluation process,as well as the feedback and adjustment by the results.Then this research analyzes 3 adaptive management strategies of urban green infrastructure,including extensive collaboration of multi-stakeholders,implementation of design experiments,and continuous performance monitoring.The application of ecosystem services evaluation in green infrastructure planning and design practice includes providing quantitative basis for policy making,offering performance-based criteria for standards setting,and affording cost-benefit analysis for project construction.In the aspect of providing quantitative basis for policy making,this research discusses the relevant management factors and the application of different policies.In terms of offering performance-based criteria for certification assessment,the relevant standards are classified into two types:project certificating standards and management effect analysis benchmarks.And in terms of affording cost-benefit analysis for project construction,this research analyzes the influential factors and the characteristics of green infrastructure cost-benefits.Then this research focuses on green infrastructure in Wuhan city area.Based on the green infrastructure ecosystem service classification proposed in the former part,the remote sensing images and other related materials,this research evaluates the economic value of 10 ecosystem services(water provisioning,agricultural production,runoff mitigation,water purification,carbon sequestration and oxygen releasing,air purification,noise reduction,climate regulation,biodiversity conservation and recreation)in the urban central district,urban developing district and urban suburb district from 1987 to 2015 by using multiple evaluation methods.Then this research analyzes and compares the value of ecosystem services in different spatial and different temporal ranges,and summarizes the improving strategies of green infrastructure ecosystem services in Wuhan.The results show that the total value of green infrastructure ecosystem services in Wuhan in 2015 is 114.297 billion yuan.The monetary value of ecosystem services provided by urban suburb district,urban developing district and urban central district accounted for 58.39%,30.95%and 10.66%respectively.However,from the perspective of supply and demand balance,only water supply can achieve a balance between the city's supply and demand.Some other kinds of ecosystem services,such as agricultural production,carbon fixation,air purification,the supplying proportion of the overall demand for the city is relatively low.In terms of temporal change,from 1987 to 1915,The value of urban green infrastructure regulating and supporting services in Wuhan decreased by 13.37%,while the value of cultural services increased by 25.84%.Finally,this research summarizes the optimizing and improving strategies of urban green infrastructure in Wuhan.At the regional level,the green infrastructure across different regions should be planned and managed holistically,the green infrastructure in different regions should be complementary with each other by their advantages,and a network of regional ecological corridors should be established.At the municipal level,the ecological bottom line should be delimited and protected,the overall water system should be preserved and restored,and the urban forests should be conserved and improved.At the urban developing area level,the urban green wedges should be strengthened,the urban development should be guided rationally and the recreational open space around the city should be created.At the urban central district level,the overall urban green infrastructure network space should be optimized,using green infrastructure to improve urban rainwater management should be promoted,and a variety of different green infrastructure can be the supplement of urban green space.