Land Use Dynamics and Ecosystem Service Value Changes in the Yangtze River Delta Urban Agglomeration Under Different Scenarios

Urban agglomerations,serving as pivotal centers of human activity,undergo swift alterations in ecosystem services prompted by shifts in land utilization.Strengthening the monitoring of ecosystem services in present and future urban agglomerations contributes to the rational planning of these areas and enhances the well-being of their inhabitants.Here,we analyzed land use conversion in the Yangtze River Delta(YRD)urban agglomeration during 1990-2020 and discussed the spatiotemporal response and main drivers of changes in ecosystem service value(ESV).By considering the different development strategic directions described in land use planning policies,we predicted land use conversion and its impact on ESV using the Future Land Use Simulation(FLUS)model in three scenari-os in 2025 and 2030.Results show that:1)from 1990 to 2020,land use change is mainly manifested as the continuous expansion of con-struction land to cultivated land.Among the reduced cultivated land,82.2%were occupied by construction land.2)The land use types conversion caused a loss of 21.85 billion yuan(RMB)in ESV during 1990-2020.Moreover,the large reduction of cultivated land area led to the continuous decline of food production value,accounting for 13%of the total ESV loss.3)From 2020 to 2030,land use change will mainly focus on Yangzhou and Zhenjiang in central Jiangsu Province and Taizhou in southern Zhejiang Province.Under the BAU(natural development)and ED(cultivated land protection)scenarios,construction land expansion remains dominant.In contrast,under the EP(ecological protection)scenario,the areas of water bodies and forest land increase significantly.Among the different scenarios,ESV is highest in the EP scenario,making it the optimal solution for sustainable land use.It can be seen that the space use conflict among urban,agriculture and ecology is a key factor leading to ESV change in the urban agglomeration of Yangtze River Delta.There-fore,it is crucial to maintain spatial land use coordination.Our findings provide suggestions for scientific and rational land use planning for the urban agglomeration.

Industrial carbon emissions and influencing factors in the Yangtze River Delta urban agglomeration

This paper calculates the industrial carbon emissions of the Yangtze River Delta urban agglomeration over the period 2006-2013. An empirical analysis is conducted to find out the influencing factors of industrial carbon emissions of the Yangtze River Delta urban agglomeration, using a spatial Durbin panel model. The results show that cities with larger industrial carbon emissions often enjoy low annual growth rates, while the cities with smaller ones enjoy higher annual growth rate; There exists a comparatively strong positive correlation in space in per capita carbon emission; urbanization, and total population. GDP per capita and international trade are the main influencing factors of industrial carbon emissions; There are spatial spillover effects on international trade and urbanization of neighboring cities, which have a significant impact on local industrial carbon emissions.

Coupling Coordination Relationship between Ecological Human Settlements and the Happiness Levels of Residents in the Yangtze River Delta Urban Agglomeration

Promoting the coordinated development of ecological human settlements and the happiness levels of residents will help to promote people-centered high-quality development.This study was based on the 2011-2021 data of the Yangtze River Delta urban agglomeration,and constructed an evaluation index system of ecological human settlements and the happiness levels of residents.The entropy value method,coupling coordination degree model,Dagum Gini coefficient and Geodetector model were used to explore the coupling coordination relationship and influencing factors of these two systems.The findings indicate that ecological human settlements and the happiness levels of residents in the Yangtze River Delta urban agglomeration have shown an upward trend over time.By 2021,the overall level of the region had significantly improved.The coupling coordination level between these two systems has gradually increased,showing a spatial distribution pattern of high in the east and low in the west.The Dagum Gini coefficient shows a fluctuating downward trend in the overall and intra-regional differences,with the largest inter-regional difference between Shanghai and Anhui,and the inter-regional difference is the main source of the spatial differences.Economic development level(Eco)was the main factor influencing the coupling coordination of the two systems from 2011 to 2021.The results of this study provide references for constructing ecological human settlements and enhancing the happiness levels of residents.

Measurement of Digital Economy Development Level in Yangtze River Delta and Its Influence on Ecological Efficiency

Based on the panel data of 41 cities in the Yangtze River Delta from 2007 to 2018,this paper empirically tests the impact of digital economy development on urban ecological efficiency in the Yangtze River Delta.The results show that the development level of digital economy in Yangtze River Delta urban agglomeration is fluctuating and rising;the development of digital economy has a significant positive role in promoting the improvement of urban ecological efficiency;there is significant regional heterogeneity in the promotion of ecological efficiency by digital economy,especially in central cities.

The Effect of Urban Agglomeration Expansion on PM_(2.5) Concentrations: Evidence from a Quasi-natural Experiment

This study constructs a quasi-natural experiment based on the expansion of the Yangtze River Delta urban agglomeration(YRDUA) of China in 2010 to investigate the impact and inner mechanism of urban agglomeration expansion on fine particulate matter(PM_(2.5)) concentrations through propensity scores in difference-in-differences models(PSM-DID) using panel data from 286 prefecturelevel cities in China from 2003 to 2016. The results show that 1) urban agglomeration expansion contributes to an overall decrease in PM_(2.5)concentration, which is mainly achieved from the original cities. For the new cities, on the other hand, the expansion significantly increases the local PM_(2.5)concentration. 2) In the long term, the significant influence of urban agglomeration expansion on PM_(2.5)concentration lasts for three years and gradually decreases. A series of robustness tests confirm the applicability of the PSM-DID model.3) Cities with weaker government regulation, a better educated population and higher per capita income present stronger PM_(2.5)reduction effects. 4) Urban agglomeration expansion affects the PM_(2.5)concentration mainly through industrial transfer and population migration, which cause a decrease in the PM_(2.5)concentration in the original cities and an increase in the PM_(2.5)concentration in the new cities.Corresponding policy suggestions are proposed based on the conclusions.

Advantages and dynamics of urban agglomeration development on Yangtze River Delta

Urban agglomeration on Yangtze River Delta （UA-YRD） had some advantages in the aspects of water, land, ecological environment, location and transportation. Relying on the resource-environment bases and other advantages, UA-YRD has achieved great development. Based on index system and model of comprehensive evaluation, the paper calculates the development level of UA-YRD since 1978. The result shows that from 1978 to 2007, the development level increased year by year at development could be divided into three an annual rate of 0.0333, and the process of stages, i.e. low-speed development stage （1978-1991）, rapid development stage （1991-2000）, and high-speed development stage （2000-2007）. The speeds are 0.0083, 0.0356 and 0.0766, respectively. During the 30-year development, foreign economic activity has the greatest effect on development, followed by transportation, industrial economic activity and telecommunication （in order）. Additionally, different driving forces have different effects in different stages. The paper suggests that more attention should be paid to the high-speed development stage and the important driving forces to drive its development. At the same time, the limitation of resource and environment should not be neglected and a long effective mechanism needs to be established to sustain harmonious development among the UA development, resource utilization and environmental protection. Some comparative studies should be carried out urgently to support and promote sustainable development of UA effectively, especially towards evolution, driving forces and braking forces.

Green economic efficiency in the Yangtze River Delta:spatiotemporal evolution and influencing factors

Based on economic-social-resource-environment perspective,which people’s welfare was considered compared with the traditional perspective,using SSU and PP model,spatial analysis method,spatial econometric model to study green economy efficiency(GRE)of 26 Cities in the Yangtze River Delta from 2005 to 2015.The results show the following:Corrected GRE is markedly lower than conventional efficiency;Stage characteristics are obvious of GRE.An overall spatial pattern has emerged of lower efficiency in the east and higher efficiency in the west,and exist clear signs of spatial agglomeration.The spatial Dubin model has abetter fitting effect.The biggest direct effect on local green economic efficiency and spatial spillover effects on nearby areas is proportion of tertiary industry.

The Effects of Tourism Industry Agglomeration on Tourism Environmental Carrying Capacity: Evidence from a Panel Threshold Model

By utilizing the panel data of 26 cities in the Yangtze River Delta urban agglomeration of China from 2000 to 2018, this study constructs a panel threshold model to examine the nonlinear relationship between Tourism Environmental Carrying Capacity(TECC) and Tourism Industry Agglomeration(TIA). TECC is evaluated based on the Driver-Pressure-State-Impact-Response(DPSIR) model, and TIA is estimated by the location quotient index.The analysis reveals that TIA and TECC both show growth trends and significant regional differences among the 26cities, but the latter fluctuates at certain stages. Moreover, TIA has a significant double threshold effect on TECC,which shows that the positive impact of TIA is enhanced initially but then weakens afterwards. Theoretically, this study contributes to enriching the current literature on TECC from the perspective of TIA. Practically, it could help local governments effectively arrange agglomerations to promote the sustainable development of the tourism industry in China.