| After long-period development,the connotation of the "two mountain theory",lucid water and green mountains are mountains rich in gold and silver,has been continuously enriched and improved to guide the Chinese to respect and protect nature with practical actions.Ecosystem service value(ESV)is a powerful indicator to reveal the dialectical and unified relationship between "lucid water and green mountains" and "golden mountain and silver mountain".It represents the huge value contained in the ecosystem through the evaluation of the benefits brought by the natural environment to mankind.At the same time,the output of ecosystem services is closely related to meteorological,hydrological,soil,vegetation,biology and other factors.Only a strong and stable ecosystem can constantly produce ecosystem services.Therefore,as a quantitative index,ecosystem service value is a comprehensive representation of ecosystem status.The main significance of ecological environment researches is to clarify the evolution process and development mechanism of environment where human live in,and find potential ecological security risks in time.However,due to the uncertainty of ecological risk,its connotation and impact are not fully specific,which brings some challenges to the risk assessment.With both economic and social attributes and natural ecological attributes,ecosystem service value is an effective factor in the research of human-land relationship.At present,it has been creatively incorporated into the category of ecological risk assessment by many scholars.This paper uses the equivalent factor method to calculate the ESV of the Yangtze River Delta Urban Agglomeration in 2000,2010 and 2020.Firstly,the equivalent system of ecosystem service value per unit area in China is modified by rainfall,vegetation net primary productivity(NPP)and soil conservation,and the dynamic equivalent factors in line with the time change and ecological characteristics of cities in the study area are obtained.Then,the ecosystem service value is caught in combination with Globe Land30,land use data.ESV change refers to ecosystem loss and is included in the ESRISK framework to evaluate the stability of ecosystem.The framework also includes the dimension of ecosystem risk probability,which is measured by seven indicators: slope,NPP,vegetation coverage change,night light intensity change,impervious surface proportion change,ecological connectivity and landscape vulnerability.In this paper,the corresponding remote sensing data products are collected,calculated and counted in turn,and the weight of each index is determined by entropy method for integration.In addition,this paper also connects the individual ecosystem services with the United Nations Sustainable Development Goals(SDGs),and quantifies the degree of regional sustainable development by the relationship between supply and demand of ecosystem services.Finally,the ecological risk status of the long-time series of Yangtze River Delta Urban Agglomeration is measured from the two aspects of ecosystem stability and sustainability.The main findings include:(1)The ecological condition of the study area is good.The rainfall was abundant and stable from2000 to 2020,and the NPP,soil conservation showed an upward trend,which was significantly higher than the national average level,indicating that the ecological environment of the Yangtze River Delta Urban Agglomeration was superior and showed the potential to continue to improve.The data of the corresponding years of the above ecological parameters were used for the dynamic correction of ecosystem service value equivalent to make the equivalent system fit the development status of the study area.Taking the prefecture and city as the unit to calculate the ecological parameters is used to modify the regional ecosystem service value equivalent,which makes the equivalent system different within the study area and enhances its pertinence and applicability.(2)The ecological ESV is evaluated based on the urban land area obtained by the ecosystem service equivalent system after localization correction and interannual correction.The results show that the overall level of the study area has increased steadily,reaching 2401.626 billion yuan,2648.916 billion yuan and 3241.368 billion yuan in 2000,2010 and 2020 respectively,which are 148.72%,30.70% and 15.33% of the regional GDP respectively.In the case of rapid development,the value of ecosystem services still shows an upward trend,indicating that the ecological environment of the Yangtze River Delta Urban Agglomeration has been better managed and protected in the process of integrated development.Within the study area,the output of ecosystem service value in Hangzhou,Suzhou and Anqing has always been at the highest level.As of 2020,the ecosystem service value of these three cities was 320.505 billion yuan,291.836 billion yuan and 285.743 billion yuan respectively.(3)From 2000 to 2020,the ecosystem service value of cities in the study area generally increased,and only Nantong and Zhoushan decreased slightly,reflecting the improvement of ecosystem conditions in the study area.The ecosystem service value of cities in the Yangtze River Delta Urban Agglomeration is used to measure the ecosystem loss within the scope of administrative regionalization in the framework of ESRISK.Combined with the local terrain,ecological stress,ecological connectivity and landscape vulnerability,it is calculated that there were five cities with high ecosystem stability from 2000 to 2010;From 2010 to 2020,the number of cities with high ecological stability reached 17.(4)In 2010,the demand of the Yangtze River Delta Urban Agglomeration for the food production service function of the ecosystem was 144.891 billion yuan,and the value of the ecosystem supply was 115.524 billion yuan.Therefore,the supply-demand ratio of this service function was 0.7973,and the value in 2020 was 0.7459,which was used to characterize the completion of the SDGs2 hunger eradication goal in 2010 and 2020,79.73% and 74.59% respectively.In 2010,the supply-demand ratios of hydrological regulation,gas regulation and climate regulation services in the study area were 94.46,11.30 and 12.66 respectively,and the corresponding values in 2020 were108.04,13.74 and 11.24.The calculation results show that the Yangtze River Delta Urban Agglomeration has achieved better in SDGs6 clean water source,SDGs7 clean energy and SDGs13 climate response goals.The supply-demand ratios of the four service functions in 2010 and 2020 were 29.81 and 30.94 respectively.The overall ecological sustainability is pretty good.(5)From the two dimensions of ecosystem stability and sustainability,Anqing,Tongling,Chizhou and Xuancheng in Anhui Province,Wuxi in Jiangsu Province and Jinhua in Zhejiang Province are the cities with the best condition of ecological risk in the 27 cities of the Yangtze River Delta Urban Agglomeration.These cities have achieved a significant increase in the value of ecosystem services,and the supply-demand relationship of ecosystem services is good.They can not only meet their basic needs for ecological resources,but also provide a solid guarantee for the overall ecological risk of urban agglomeration.Cities along the coast of Hangzhou Bay,including Shanghai,Hangzhou,Ningbo and Suzhou,also showed an improvement trend during the study period. |
PDF Full Text Request