Spatial-temporal Changes Of Ecosystem Services In Yangtze River Delta Urban Agglomeration Based On Gini Coefficient

As one of the six major urban agglomerations in the world,the Yangtze River Delta urban agglomeration is also one of the regions with the most developed economy,the closest external contact and the largest number of migrants in China.The Urban agglomeration in the Yangtze River Delta plays an important strategic role in driving the surrounding economy and deepening the foreign economic and trade exchanges.However,in the past few decades,the rapid development of industrialization and urbanization has lead to the damage of the internal ecological environment of urban agglomeration.In addition,the regional economic development and ecosystem service function have also been negatively affected.The spatial-temporal changes of ecosystem services in this region can be studied systematically to understand the supply and demand of various ecosystem services among different cities in the region and in different development stages of the same city,which is particularly significant for the coordinated and sustainable development of economy,society and ecology in this region in the future.The author will take 26 cities in Yangtze river delta urban agglomeration as the study area,and then make the quantitative assessment of the region’s supply and demand of ecosystem services in 2010,2015,2020.By using the Gini coefficient and the supply and demand factor,the relationship between supply and demand of ecosystem services will be analyzed.In addition,the Yangtze river delta urban agglomerations will be divided according to the development of ecology.Finally,those conclusions will have a great influence on cities from resource utilization,environmental protection,urban management,future development and regional coordination.The main conclusions are as follows:(1)There are spatial-temporal differences in land use change of urban agglomerations in the Yangtze River Delta.Compared with 2010,cultivated land area decreased by 7.29% and construction land increased by 33.7% in 2020,while woodland,grassland and water area did not change much.In terms of cities,Shanghai saw the largest decrease in the area of arable land(884.3 sq km)and the largest increase in the area of construction land(834.7 sq km).Among other provinces,Jiangsu province saw the largest decrease in urban average cultivated land,while Anhui Province saw the least decrease in urban average cultivated land.(2)The ecosystem service supply of urban agglomerations in the Yangtze River Delta also has spatial and temporal differences.The total value of ecosystem service supply in 2010,2015 and 2020 is 472.334 billion yuan and 468.777 billion yuan respectively.From 2010 to 2020,The overall value of ecosystem service supply in the Yangtze River Delta urban agglomeration shows a declining trend.From the perspective of space,the value of ecosystem service supply in Zhejiang province and Anhui Province is the highest,and the value of ecosystem service supply in Shanghai is the lowest,accounting for only 1.40% of the total value of ecosystem service supply in the Yangtze River Delta urban agglomeration(3)The value of ecosystem service demand of urban agglomerations in the Yangtze River Delta showed an upward trend over time.From the perspective of space,Jiangsu province and Zhejiang Province have the highest proportion of ecosystem service demand in 2020,accounting for 36.95% and 30.49%,respectively.The demand for ecosystem services in Anhui province and Shanghai was 23.87% and 8.69%,respectively.(4)From the perspective of comprehensive supply and demand coefficient,the supply and demand coefficient of 15 cities decreases over time,while that of 11 cities increases.This shows that the gap between supply and demand in most cities gradually decreases with urban development.The comprehensive Gini coefficient was 0.34 in2010 and decreased to 0.32 in 2020,indicating that the supply-demand relationship of urban agglomerations in the Yangtze River Delta is balanced over time.(5)According to the supply and demand coefficient and Gini coefficient,the 26 cities in the Yangtze River Delta urban agglomeration are divided into three types,and then divided again according to the change of time.As a result,the differentiated development ideas will be put forward in order to provide reference for the ecosystem planning and urban construction and development of the Yangtze River Delta urban agglomeration.The author will quantitatively evaluate the characteristics of supply and demand of ecosystem services,analyze the spatio-temporal changes of supply and demand,and discuss the supply and demand of ecosystem services in cities of the Yangtze River Delta so as to carry out ecological zoning according to the status quo of different regions as well as put forward corresponding development suggestions and countermeasures for cities of different regions.It is of great significance to promote the coordinated and healthy development of cities in the Yangtze River Delta region.