Integration of land ecological consolidation and ecosystem product value realization: A case from the Yangtze riverside industrial park in Changzhou, China.

Traditional industries and industrialization have led to widespread environmental pollution and ecosystem degradation in major river basins globally. Strategies centered on ecological restoration and ecological economy are emerging as essential tools for effective environmental governance. This study aims to investigate how a multifaceted framework for land ecological consolidation, with various developmental goals, can effectively support ecological restoration and sustainability. Through quantitative analysis and in-depth interviews, we investigated the case of Yangtze riverside chemical industrial park in Changzhou. This park pursues ecological and economic sustainability through chemical industry transformation, ecological restoration and protection, ecological management, and ecological industry development. The results show that this practice established a multi-objective action framework rooted in urban renewal, land consolidation, ecological restoration, industrial transformation, and rural revitalization. Through multiplanning integration, integrated implementation and full-cycle profit distribution, the aim of ecological protection has been initially achieved, offering a crucial guarantee for sustainable development. A total of 96.47 ha ecological space expanded, which can generate ecological product worth CNY 7.283 billion, alongside a net economic benefit of CNY 978 million over three decades. The top-down ecological responsibilities, coupled with local developmental demands, have stimulated collaborations within a bottom-up endogenous network comprising government, enterprises, and residents.

Effect of urbanization and urban forests on water quality improvement in the Yangtze River Delta: A case study in Hangzhou, China.

In the context of rapid global urbanization, the sustainable development of ecosystems should be considered. Accordingly, the Planetary Boundaries theory posits that reducing the amount of nitrogen and phosphorus pollutants entering bodies of water is necessary as excess levels may harm the aquatic environment and reduce in water quality. Thus, based on the long-term monitoring data of representative urban rivers in the Yangtze River Delta region, we evaluated the nitrogen and phosphorus pollution of water bodies in different urbanization stages and further quantified the effect of urban forests on water quality improvement. The results showed that, with the continuous progression of urbanization, the proportion of impervious surface area increased, along with the levels of nitrogen and phosphorus pollution in water bodies. The critical period of water quality deterioration in urban rivers occurred during the medium urbanization level when the proportion of impervious surface area reached 55-65 %, and the probability of an abrupt increase in total nitrogen (TN) and total phosphorus (TP) concentration exceeded 95 %. However, increasing the area of urban forests during this period reduced TN pollution by 36.64 % and TP pollution by 49.03 %. The results of this study support the expansion of urban forests during the medium urbanization stage to improve water quality. Furthermore, our results provide a reference and theoretical basis for urban forest construction as a key aspect of the sustainable development of the urban ecosystem in the Yangtze River Delta and similar regions around world.

Regional policy options for carbon peaking in the Yangtze River Delta under uncertainty.

The Yangtze River Delta (YRD) region plays a crucial role in achieving China's carbon peaking goal. However, due to uncertainties surrounding future economic growth, energy consumption, energy structure, and population, the attainment of carbon peaking in this region remains uncertain. To address this issue, this study utilized the generalized Divisia index method to analyze the driving factors of carbon emissions, including economy, energy, investment, and population. Subsequently, Monte Carlo simulations were combined with scenario analysis to dynamically explore the peak path of regional heterogeneity in the YRD from 2022 to 2035 under uncertain conditions. The findings highlighted that economic uncertainty has the most significant impact on carbon emissions. Furthermore, reducing energy intensity and promoting the transformation of the energy consumption structure contribute to carbon reduction. The study also revealed that the carbon peak in the YRD exhibits regional heterogeneity. According to the baseline scenario, carbon emissions in the YRD will not peak before 2035. However, under the low-carbon development scenario, the carbon emissions of Zhejiang and Shanghai will peak before 2030. Moreover, under the enhanced emission reduction (EE) scenario, carbon emissions in Jiangsu, Zhejiang, and Shanghai will peak before 2025, while Anhui will reach its peak before 2030. Collectively, the entire YRD region is forecasted to attain a carbon emissions peak of 2.29 billion tons by 2025 under the EE scenario. This study provides valuable insights into the carbon emission trajectories of the YRD region under uncertain conditions. The findings can be instrumental in formulating carbon peaking policies that account for regional heterogeneity.

Exploring the spatial effects and influencing mechanism of ozone concentration in the Yangtze River Delta urban agglomerations of China.

Ground-level ozone (O3) pollution has emerged as a significant concern impacting air quality in urban agglomerations, primarily driven by meteorological conditions and social-economic factors. However, previous studies have neglected to comprehensively reveal the spatial distribution and driving mechanism of O3 pollution. Based on the O3 monitoring data of 41 cities in the Yangtze River Delta (YRD) from 2014 to 2021, a comprehensive analysis framework of spatial analysis-spatial econometric regression was constructed to reveal the driving mechanism of O3 pollution. The results revealed the following: (1) O3 concentrations in the YRD exhibited a general increasing and then decreasing trend, indicating an improvement in pollution levels. The areas with higher O3 concentration are mainly the cities concentrated in central and southern Jiangsu, Shanghai, and northern Zhejiang. (2) The change of O3 concentration and distribution is the result of various factors. The effect of urbanization on O3 concentrations followed an inverted U-shaped curve, which implies that achieving higher quality urbanization is essential for effectively controlling urban O3 pollution. Traffic conditions and energy consumption have significant direct positive influences on O3 concentrations and spatial spillover effects. The indirect pollution contribution, considering economic weight, accounted for about 35%. Thus, addressing overall regional energy consumption and implementing traffic source regulations are crucial paths for O3 pollution control in the YRD. (3) Meteorological conditions play a certain role in regulating the O3 concentration. Higher wind speed will promote the diffusion of O3 and increase the O3 concentration in the surrounding city. These findings provide valuable insights for designing effective policies to improve air quality and mitigate ozone pollution in urban agglomeration area.

Spatial price differences of medical services: evidence from the Yangtze River Delta in China.

BACKGROUND: Price differences of medical services across regions may affect equity in health financing. This study aimed to estimate the spatial price index of medical services to measure price levels across regions in the Yangtze River Delta, China. METHODS: Gini-Éltetö-Köves-Szulc method and minimum spanning tree method based on the purchasing power parities were used in this study. RESULTS: According to the Gini-Éltetö-Köves-Szulc method, Shanghai and Anhui province had price levels that are 127.55% and 103.45% respectively of the price level in Zhejiang province, whereas in Jiangsu medical services were priced at 92.71% of that in Zhejiang province. The spatial price index of medical services in the Yangtze River Delta based on the minimum spanning tree method provided similar results. CONCLUSIONS: Regions in the Yangtze River Delta had significant gaps in medical services price levels. And the price levels tended to not correlate with socioeconomic levels. It is necessary to promote the regional coordination of medical services price and better achieve equity in health.

Transmission paths and source areas of near-surface ozone pollution in the Yangtze River delta region, China from 2015 to 2021.

Near-ground ozone in the Yangtze River Delta (YRD) region has become one of the main air pollutants that threaten the health of residents. However, to date, the transport behavior and source areas of ozone in the YRD region have not been systematically analyzed. In this study, by combining the ozone observational record with a HYSPLIT (hybrid single-particle Lagrangian integrated trajectory) model, we tried to reveal the spatiotemporal regularity of the airflow transport trajectory of ozone. Spatially, high ozone concentrations mainly clustered in industrial cities and resource-based cities. Temporally, the center of the ozone pollution shifted westward of Nanjing from 2015 to 2021. With the passage of time, the influence of meteorological elements on the ozone concentration in the YRD region gradually weakened. Marine atmosphere had the most significant impact on the transmission path of ozone in Shanghai, of which the trajectory frequency in 2021 accounted for 64.21% of the total frequency. The transmission trajectory of ozone in summer was different from that in other seasons, and its transmission trajectory was mainly composed of four medium-distance transmission paths: North China-Bohai Sea, East China Sea-West Pacific Ocean, Philippine Sea, and South China Sea-South China. The contribution source areas mainly shifted to the southeast, and the emission of pollutants from the Shandong Peninsula, the Korean Peninsula-Japan, and the Philippine Sea-Taiwan area increased the impact of ozone pollution in the Shanghai area from 2019 to 2021. This study identified the regional transport path of ozone in the YRD region and provided a scientific reference for the joint prevention and control of ozone pollution in this area.

Dynamic decomposition and regional differences of urban emergy ecological footprint in the Yangtze River Delta.

Maintaining the balance between the economy and the environment and further realizing sustainable economic development has become an important topic. The existing research has not used the emergy ecological footprint model to calculate the ecological footprint of the Yangtze River Delta, nor have they used the factor decomposition method to analyze the influencing factors affecting the ecological footprint change. The differences in the emergy ecological footprint among different provinces and cities have not been studied. This study reported the emergy ecological footprint in the Yangtze River Delta region from 2008 to 2020. The Logarithmic Mean Divisia Index model (LMDI) was constructed to decompose the change of emergy ecological footprint into the land structure, technology, economy, and population factors to screen the main influencing factors. Gini coefficient and Theil index were used to further analyze the main influencing factors which caused the differences in the footprints at regional and intra-regional levels. The results show that: (1) The fluctuation of the per capita emergy ecological footprint in the Yangtze River Delta region has decreased, while the fluctuation of the per capita emergy ecological carrying capacity has increased. However, the per capita emergy ecological deficit is still high, where the sustainable development of the regional economy is not optimistic. (2) Technology and economy are the main factors affecting the emergy ecological footprint of the Yangtze River Delta. (3) Regional differences refer to the differences between different provinces, while intra-regional differences refer to the difference between cities within the province. In the Yangtze River Delta region, the intra-regional differences are the main reasons causing the technical differences, while the regional differences are the main reasons causing the economic differences. The significance of the study is that scientific analysis of the sustainable development status and utilization degree of resources and environment are vital for realizing the sustainable development of the Yangtze River Delta region. By decomposing the factors affecting sustainable development, the regional differences of these factors could be analyzed and serve as a theoretical basis for local governments to formulate policies to minimise the emergy ecological footprint of a targeted region.

Differential characteristics of carbon emission efficiency and coordinated emission reduction pathways under different stages of economic development: Evidence from the Yangtze River Delta, China.

Regional carbon emission efficiency (CEE) has differentiated characteristics under different economic development stages and patterns, and identifying such characteristics is important for formulating corresponding policies for high-quality regional development. Using input‒output data related to economic development and energy consumption, a comprehensive evaluation model of the Super-SBM and Malmquist‒Luenberger (ML) index is constructed to evaluate the spatial and temporal changes and driving forces of CEE. Based on this index, a proposal is designed for collaborative carbon emission reduction zoning. The results indicate that the CEE of the Yangtze River Delta shows a fluctuating upward trend with obvious spatial agglomeration characteristics, and CEE changes are closely related to economic development stages. The annual average CEE values in each stage show positive changes, indicating that economic development gradually evolves to low carbonization levels. Moreover, CEE improvement gradually shifts from being driven by efficiency changes to being driven by technological changes. Finally, according to the characteristics of total carbon emissions and the efficiency of different cities, a synergistic emission reduction path is proposed with four aspects: land use optimization, ecological co-preservation, innovation cooperation and low carbon development.

Spatial distribution and source apportionment of surface soil's polycyclic aromatic hydrocarbons in the Yangtze River Delta.

Soil acts as a crucial reservoir of polycyclic aromatic hydrocarbons (PAHs) in the environment, and its PAH content serves as a significant indicator of regional PAH pollution. Monitoring PAH levels in soil is important for assessing the potential risks to human and environmental health. In this study, 53 surface soil samples were collected from the Yangtze River Delta. These samples were monitored for 16 priority PAHs. Pollution levels, compositional profiles, and source differences of soil PAHs were analyzed among different regions, urban and rural areas, and functional zones. The total PAH content (Σ16PAHs) in the surface soil of the Yangtze River Delta was 2326.01 ± 2901.53 ng/g. High-ring PAHs (4-6 rings) accounted for the predominant portion (85.50%) of total PAHs. The average pollution level of soil PAHs in Jiangsu Province (2651.92 ± 3242.87 ng/g) was significantly higher than that of Zhejiang Province (2001.44 ± 2621.71 ng/g) and Shanghai (1669.13 ± 1758.34 ng/g), and high-ring PAHs constituted a predominant portion in these three regions. There was no significant difference in the PAH content between urban and rural areas. In different functional areas, automobile stations exhibited the highest PAH levels among the functional zones analyzed, with traffic emissions identified as a major source of soil PAH in this area. The primary factors influencing the distribution of soil PAHs in the study area were the duration of urbanization exposure (r = 0.753, p < 0.01) and soil organic carbon content (r = 0.452, p < 0.01). This provides novel evidence for the cumulative build-up of PAHs during urbanization. The positive matrix factorization model was used to analyze the sources of PAHs in the surface soil of the Yangtze River Delta, revealing that biomass and coal combustion (60.19%) and traffic emissions and coal combustion (31.82%) were the primary sources of PAHs in the region.

Synergistic analysis of atmospheric pollutants NO2 and PM2.5 based on land use regression models: a case study of the Yangtze River Delta, China.

Air pollution is considered one of the greatest threats to human health. This study combines a land use regression (LUR) model with satellite measurements and a distributed-lagged non-linear model (DLNM). It aims to predict high-resolution ground-level concentrations of nitrogen dioxide (NO2) and particulate matter 2.5 (PM2.5) in the Yangtze River Delta (YRD) and reveal the mechanisms of influence between NO2 and PM2.5 and precursors and meteorological factors. Results showed that the annual average NO2 and PM2.5 in the YRD urban agglomeration 2019 were 39.5 µg/m3 and 37.5 µg/m3, respectively. The seasonal variation of NO2 and PM2.5 showed winter > spring > autumn > summer. There is a compelling and complex relationship between NO2 and PM2.5. Predictors indicate that latitude (Y), surface pressure (P), ozone (O3), carbon monoxide (CO), aerosol optical depth (AOD), residential, and rangeland have positive impacts on NO2 and PM2.5. In contrast, temperature (T), precipitation (PRE), and industrial trees hurt NO2 and PM2.5. DLNM model results show that NO2 and PM2.5 had significant associations with the included precursors and meteorological elements, with lagged and non-linear effects observed. Satellite data could help significantly increase the accuracy of LUR models; the R2 of tenfold cross-validation was enhanced by 0.18-0.22. In 2019, PM2.5 will be the dominant pollutant in the YRD, and NO2 showed a high value in the central and eastern parts of the YRD. High concentrations of NO2 and PM2.5 are present in 86% of the YRD, meaning that residents will have difficulty avoiding exposure to these two high pollution levels.

Effects of production-living-ecological space changes on the ecosystem service value of the Yangtze River Delta urban agglomeration in China.

In the process of urbanization, exploring the relationship between production-living-ecological space (PLES) and ecosystem service value (ESV) is a major scientific issue in promoting regional sustainable development. The Yangtze River Delta (YRD) urban agglomeration is an ideal study area, which has the highest urbanization rate in China. Based on Landsat TM/ETM imaging data from 2005, 2010, 2015, and 2018, this study established a land use classification system of PLES. The spatial and temporal characteristics of PLES and ESV were analyzed, and the response of ESV to changes in PLES was investigated based on the elasticity formula. The results showed that from 2005 to 2018, production space and ecological space were the main types of PLES and exhibited an imbalance in transformation. Production space was the main transfer type, and living space significantly expanded. Moreover, from 2005 to 2018, the ESV of the YRD urban agglomeration showed an increasing and then decreasing trend. ESV presented a "high in the southwest and low in the northeast" spatial pattern. Furthermore, ESV was sensitive to changes in PLES, showing a trend of ecological space > production space > living space. However, the sensitivity of ESV to changes in PLES varied according to urbanization level.

Spatial-temporal evaluation of urban resilience in the Yangtze River Delta from the perspective of the coupling coordination degree.

Scientific evaluation of urban resilience will help to improve the ability of self-prevention and self-recovery when facing internal and external pressure. However, existing studies are on basis of the overall perspective of the urban resilience evaluation index system to measure urban resilience, often ignoring the coupling and coordination degree among indicators. Therefore, an empirical analysis is developed, which is used to measure the urban resilience of eight cities in the Yangtze River Delta urban agglomeration from 2010 to 2019 from the perspective of coupling coordination degree based on the urban resilience evaluation index system. The empirical results show that (1) In time, the eight cities' resilience fluctuated dynamically and varied to different degrees. It presents the spatial distribution characteristics of "high in the center and low in the periphery" in space. (2) In time, the coupling coordination degree in the eight cities fluctuated slightly. The spatial distribution pattern of "high in the center and low in the periphery" was formed in terms of space. (3) There is a long-term stable relationship between urban resilience and the coupling coordination degree among all indicators. In a certain sense, the higher the coupling coordination degree is, the higher the urban resilience is. These results can improve urban resilience to some extent and make cities more resilient in the future collaborative development process, and provide a way to evaluate urban resilience at different spatial-temporal scales.

Dramatic decline of observed atmospheric CO2 and CH4 during the COVID-19 lockdown over the Yangtze River Delta of China.

The temporal variation of greenhouse gas concentrations in China during the COVID-19 lockdown in China is analyzed in this work using high resolution measurements of near surface △CO2, △CH4 and △CO concentrations above the background conditions at Lin'an station (LAN), a regional background station in the Yangtze River Delta region. During the pre-lockdown observational period (IOP-1), both △CO2 and △CH4 exhibited a significant increasing trend relative to the 2011-2019 climatological mean. The reduction of △CO2, △CH4 and △CO during the lockdown observational period (IOP-2) (which also coincided with the Chinese New Year Holiday) reached up to 15.0 ppm, 14.2 ppb and 146.8 ppb, respectively, and a reduction of △CO2/△CO probably due to a dramatic reduction from industrial emissions. △CO2, △CH4 and △CO were observed to keep declining during the post-lockdown easing phase (IOP-3), which is the synthetic result of lower than normal CO2 emissions from rural regions around LAN coupled with strong uptake of the terrestrial ecosystem. Interestingly, the trend reversed to gradual increase for all species during the later easing phase (IOP-4), with △CO2/△CO constantly increasing from IOP-2 to IOP-3 and finally IOP-4, consistent with recovery in industrial emissions associated with the staged resumption of economic activity. On average, △CO2 declined sharply throughout the days during IOP-2 but increased gradually throughout the days during IOP-4. The findings showcase the significant role of emission reduction in accounting for the dramatic changes in measured atmospheric △CO2 and △CH4 associated with the COVID-19 lockdown and recovery.

The interaction between black carbon and planetary boundary layer in the Yangtze River Delta from 2015 to 2020: Why O3 didn't decline so significantly as PM2.5.

Since the Air Pollution Prevention and Control Action Plan (air clean plan) issued in 2013, air quality has been in continuous improvement. The second stage of air clean plan since 2018 was focused on O3 controlling, but it still didn't decline so significantly as PM2.5. This study conducted a long-term observation on black carbon (BC) and utilized the observational data of other air pollutants (PM2.5, PM10, NO2, SO2, CO and O3), the meteorological elements and the vertical sounding data of PBL in Nanjing. In the daytime (08:00-20:00), PM2.5 kept decreasing from 2015 to 2020 at the rate of 4.8 µg⋅m-3⋅a-1, however, BC increased at the rate of 0.6 µg⋅m-3⋅a-1, which has led to the continuous growth of BC/PM2.5 (0.9%⋅a-1). However, during this period, O3 was relatively stable and, in 2020, it returned below its value in 2015 after slight increases in 2017 and 2018. Meanwhile, the average surface temperature had increased by around 1.0 °C during 2015-2019 at the rate of 0.3 °C⋅a-1. Also, the average height of the inversion layer had increased significantly by 494.0 and 176.7 m at 20:00 and 08:00, whose growth ratio was up to 57% and 25%, respectively. The above observation results have formed a set of chain reactions as follows. The growth of the surface BC caused the surface temperature to rise due to the increasing heating effect of BC. The continuous growth of the surface temperature made it easier for the PBL height to develop, which led to the lift of the inversion layer in the PBL and the larger atmospheric environment capacity. Ultimately, it is conducive to the diffusion of the near surface pollutants, thus helping reduce their concentrations, which offsets the increasing tendency of O3 and add to the decreasing trend of PM2.5. This phenomenon is the most remarkable in summer, with the fastest increasing rate of temperature (0.8 °C⋅a-1) and O3 (3.9 µg⋅m-3⋅a-1) during 2015-2019 (excluding 2020 to erase the great effect of COVID-19 lockdown on emissions).

Characteristics, formation, and sources of PM2.5 in 2020 in Suzhou, Yangtze River Delta, China.

Here we present seasonal chemical characteristics, formations, sources of PM2.5 in the year 2020 in Suzhou, Yangtze River Delta, China. Expectedly, organic matter (OM) found to be the most dominant component of PM2.5, with a year-average value of 10.3 ± 5.5 µg m-3, followed by NO3- (6.7 ± 6.5 µg m-3), SO42- (3.3 ± 2.5 µg m-3), NH4+ (3.2 ± 2.8 µg m-3), EC (1.1 ± 1.3 µg m-3), Cl- (0.57 ± 0.56 µg m-3), Ca2+ (0.55 ± 0.91 µg m-3), K+ (0.2 ± 1.0 µg m-3), Na+ (0.18 ± 0.45 µg m-3), and Mg2+ (0.09 ± 0.15 µg m-3). Seasonal variations of PM2.5 showed the highest average value in spring, followed by winter, fall, and summer. Meanwhile, the formation mechanisms of the major PM2.5 species (NO3-, SO42-, and OM) varied in seasons. Interestingly, NO2 may have the highest conversion rate to NO3- in spring, which might be linked with the nighttime chemistry due to the high relative humidity. Moreover, OM in summer was mainly produced by the daytime oxidation of volatile organic compounds, while local primary organic aerosols might play a significant role in other seasons. Source apportionment showed that the more-aged PM2.5 contributed significantly to the PM2.5 mass (42%), followed by the dust-related PM2.5 (38%) and the less-aged PM2.5 (21%). Potential contribution source function (PSCF) results indicated that aged PM2.5 were less affected by transportation than dust-related PM2.5.

Integrative analysis of circRNAs from Yangtze River Delta white goat neck skin tissue by high-throughput sequencing (circRNA-seq).

The Yangtze River Delta white goat is a unique goat species that can produce superior-quality brush hair. The formation of this brush hair is controlled by a series of critical genes and related signaling pathways. Circular RNAs (circRNAs), are ubiquitous endogenous non-coding RNAs that regulate many biological and physiological processes in mammals. However, little is known about the potential regulatory role of circRNAs on superior-quality brush hair formation in Yangtze River Delta white goat. In this study, high-throughput sequencing technology was used to only detect circRNAs in the neck skin tissue of normal-quality goats (NHQs) and superior-quality goats (HQs). A total of 61 803 circRNAs were identified and 32 of them were differentially expressed in the NHQ group vs. the HQ group. Functional enrichment analysis showed that the source gene of differentially expressed circRNAs (DE-circRNAs) was enriched mostly in platelet activation and the focal adhesion signal pathway. Action mechanism analysis revealed that DE-circRNAs could sponge to many identified miRNAs, including miR-31, miR-125b, miR-let-7a and miR-149-5p, which have important roles in goat hair follicle stem cell growth, hair follicle development and morphogenesis. Altogether, our findings provide a valuable basis for studying circRNAs involved in superior-quality brush hair traits and meanwhile advance our understanding of circRNA complex regulation mechanisms in Yangtze River Delta white goat skin hair follicle development.

Does air pollution inhibit manufacturing productivity in Yangtze River Delta, China? Moderating effects of temperature.

China has been experiencing serious and recurrent incidences of air pollution in recent years. The frequency and timespans of such incidences are uncertain because of variable urban weather conditions, especially temperature, that inhibit the productivity of manufacturing companies. Matching data about listed manufacturing companies in China's Yangtze River Delta urban cluster from 2003 to 2018 with data on urban air pollution and weather, we explored the effects of air pollution on corporate productivity and the moderating role of temperature. We found that air pollution significantly inhibited the productivity of these companies, which decreased by about 0.1% for 1% increase in the concentration of PM2.5. Regarding industry heterogeneity, high-energy-consumption and low-technology manufacturing industries were more sensitive to the negative effects of air pollution. Furthermore, we concluded that low temperatures played an important role in causing significant increases in the negative effects of air pollution. In the fall and winter (October to January), the lower the temperatures resulted in stronger inhibitory effects of air pollution on corporate productivity. When the average daily temperature is 0°C-3°C, the moderating effects of temperature are even more obvious. To minimize the inhibitory effects of air pollution on productivity, governments and companies should implement positive adaptions to simultaneously confront air pollution and temperature change.

Cross-administrative and downscaling environmental spatial management and control system: A zoning experiment in the Yangtze River Delta, China.

Promoting the downscaling and integration of zonal management and control of various environmental pollution sources is an effective way to systematically deal with the current high-intensity and complex environmental problems. Through single-factor and comprehensive pollutant emission intensity evaluation and cluster analysis, we built a full-coverage and cross-scale environmental spatial management and control system for pollution sources, then proposed environmental zoning patterns and pollution control strategies at three scales in the Yangtze River Delta (YRD), China. At the grid scale, the reclassified 7 types of pollution source spaces can be divided into 5 levels based on pollution emission intensity, and the most urgent environmental control subjects can be determined accordingly. Up to the county scale, combined with emission intensity and regional functions, 305 counties can be divided into 5 control intensity zones, which directly correspond to different environmental control intensity, requirements and policies. Finally, at the city scale, 41 cities can be clustered into 7 pollution control zones, which are classified and named as the three-level form of geographic location, development orientation and pollution source characteristics. Fully using the zoning units at different scales of cities, counties and grids can break the limitation of inherent administrative boundaries and allow environmental integration policies to be implemented across departments and regions, also let differentiated policies be more accurately implemented to different administrative levels and pollution source, and then truly improve the efficiency of environmental management.

Using cooperative game model of air pollution governance to study the cost sharing in Yangtze River Delta region.

To solve the increasingly serious air pollution problem, regional air pollution collaborative governance as an effective way is introduced in this paper. Firstly, this study constructs a game model of regional air pollution collaborative governance, and three classic cost sharing methods are used to allocate the cost of air pollution governance; Then the emission reduction cost of regional cooperative governance is obtained; Finally, the study makes an empirical analysis on the cost sharing of SO2 emission reduction by four local governments of the Yangtze River Delta region in 2017. The results show that: (i) The emission reduction cost of regional cooperative governance is better than that of individual governance, and in 2017 the cost of SO2 cooperative governance in Yangtze River Delta region is reduced by about 1.8% compared with the individual governance; (ii) The Shapley value method is utilized to allocate the benefits of the cooperative SO2 governance of four provinces in the Yangtze River Delta region, which indicates that all local governments can obtain certain profits from this cooperation and the cooperative alliance is stable; (iii) Collaborative governance of regional air pollution can meet the requirements of both collective rationality and individual rationality at the same time.

Assessing the fractionation and bioavailability of heavy metals in soil-rice system and the associated health risk.

This study developed a method to build relationships between chemical fractionations of heavy metals in soils and their accumulations in rice and estimate the respective contribution of each geochemical speciation in the soils from the Yangtze River Delta, China. In contaminated areas, residue and humic acid-bound fractions in soils were the main phases for most heavy metals. The mobility of heavy metals was in this following order: Cd > Pb ≈ Zn > Ni > As ≈ Cr > Hg. Transfer factors calculated by the ratios of specific fractionations of heavy metals in the soil-rice system were used to assess the capability of different metal speciation transfer from soil to rice. The carbonate and Fe/Mn oxyhydroxides bound phase had significant positive correlations with total metal concentrations in rice. Hg uptake by rice might be related to the exchangeable and carbonate-bound fractions of soil Hg. Results of PCA analysis of transfer factors estimated that the labile fractions (i.e. water soluble, exchangeable and carbonate bound) contributed more than 40% of the heavy metal accumulations in rice. Effect of organic matter and residue fraction on metals transfer was estimated to be ~ 25 to ~ 30% while contribution of humic acid and Fe/Mn oxyhydroxides-bound fractions was estimated to be ~ 20 to ~ 30%. Modified risk assessment code (mRAC) and ecological contamination index (ECI) confirmed that the soil samples were polluted by heavy metals. Soil Cd contributed more than 80% of mRAC. Contrarily, the main contributors to ECI were identified as As, Hg, Pb and Zn. The average values of total target hazard quotient (TTHQ) and Risktotal were above 1 and 10-4 respectively, implying people living in the study area were exposed to both non-carcinogenic and carcinogenic risk. As and Pb were the main contributor to high TTHQ value while As, Cd and Cr in rice contributed mostly to Risktotal value. Spatial changes of ecological risk indexes and human health risk indexes showed that the samples with high TTHQ values distributed in the area with high values of mRAC. Likewise, the area with high ECI values and with high carcinogenic risk overlapped.