Ecosystem Services Valuation Of Wetlands In Pearl River Delta

As one of the three major ecosystems of the earth,wetlands have huge ecological,economic and social benefits,and are an important ecological landscape and material basis for establishing a harmonious,civilized and sustainable living environment.Pearl river delta wetlands are rich in resources and diverse in types,which is an important guarantee for building regional ecological security.In recent decades,under the dual pressure of climate change and human activities,the wetland resources of Pearl River Delta have undergone tremendous changes,and it is urgent to carry out wetland resource monitoring and ecological service value assessment research.Therefore,taking Pearl River Delta wetland as the research object,combined with the land use data of the third phase,the study constructed a service value assessment system suitable for Pearl River Delta wetland,and used the value assessment method to evaluate the service value of Pearl River Delta wetland in 2000,2010 and 2020,and through the analysis of the value status and change process of wetland services in the whole and regional scope of Pearl River Delta in the three years,the leading function positioning of multi-scale and multi-level wetlands was realized,and the degree of urbanization development was coupled.To explore the impact of urbanization development in Pearl River Delta on the change of wetland ecological service value.The main findings are as follows:(1)Construct an ecosystem service value assessment system suitable for Pearl River Delta wetlands and determine its assessment methods.Taking the accounting specification of total ecosystem ecological value as a reference,combined with the characteristics and functions of wetlands in Pearl River Delta,the value of ecosystem services is divided into first-level classifications of economic value,social value and ecological value,and seven secondary classifications.On the basis of service value classification,the market value method,shadow engineering method and sewage treatment cost method are used to evaluate the value of wetland services.(2)The value of ecosystem services in different regions and types of wetlands in Pearl River Delta is obviously different.In 2000,the value of wetland ecological services was the lowest(115.183 billion yuan),and the highest in 2020(141.876 billion yuan),of which the value of wetland ecological services in the middle of the study area showed negative growth in 2010-2020;the Tanjiang River Basin,Xijiang River Basin,Pearl River Basin and some coastal areas became wetlands providing major ecological functions in Pearl River Delta,and wetlands in the western and eastern suburbs became wetlands that provided wetland ecosystem service support;among the individual wetland service values,fishery products,Flood control and storage contribute the most to the value of wetland services,followed by leisure tourism,which contributes the least to the value of preventing soil erosion;the types of wetlands in Pearl River Delta that provide the main service value are rivers,pits and ponds,and reservoirs.(3)The dominant function of most urban wetlands is mainly fishery products and flood control and water storage.The leading function of wetlands in most urban built-up areas is flood control and water storage,and the leading function of suburban wetlands is fishery products;the leading functions of reservoir wetland types are flood control and water storage and leisure tourism,the leading functions of river wetland types are flood control and water purification functions,the leading functions of mangrove wetland types are leisure tourism functions,the leading functions of pit and pond types are fishery products and atmospheric composition regulation,and the leading functions of lake types are flood control and water storage and leisure tourism.(4)The level of urbanization has a significant impact on the value of wetland services.From 2010 to 2020,the wetland service value and the urbanization development level of the central cities in the study area were in an unstable conflict,and human activities had a huge impact on the value of wetland services,and the change in highway density,the change in the proportion of employees in the secondary and tertiary industries,and the change in population density had a greater impact on the change in the value of wetland services in Pearl River Delta.Deeply excavating the value of wetland ecosystem services,exploring the impact of natural and human factors on wetland services,coordinating the protection of wetland leading functions according to urban location,implementing wetland management strategies,and deepening the application of wetland ecosystem service values can provide guarantees for the construction of a wetland ecological security system in Pearl River Delta.