Analysis of spatial characteristics and influencing factors of the flow network of highly educated talents from national and local perspective

Based on dynamic monitoring data on China's population, by using complex networks, spatial analysis and mathematical measurement, this study reveals the spatial characteristics and influencing factors of the network of flows of highly educated talents in the Yangtze River Delta region from the national and local perspectives. In the two perspectives, the network has strong isomorphism and certain differences. The in-flow of highly educated talents from cities with high administrative levels and more developed economies to Shanghai constitutes the core of the entire network. From a national perspective, highly educated talents tend to converge to the Yangtze River Delta region. From a local perspective, it was found that these talents cluster towards a limited number of cities in the region. From both perspectives, the flow network has developed into a "core-periphery" progressive hierarchical structure, with Shanghai becoming the sole core city. There is little difference in the influencing factors of talent mobility from both macro and meso perspectives. Highly educated talents would frequently flow between cities with strong economic development levels, and cities with high education level, scientific and technological level, complete infrastructure, and good aesthetics. However, geographical distance still plays a hindering role in the flow of highly educated talents, and factors such as cultural identity, institutional, and social modality differences among regions also have a certain effect on the flow of these talents.

Using fs/QCA to explore the influencing factors of urban green infrastructure development and its combinational drivers: the case of the Yangtze River Delta region of China

High levels of urban green infrastructure (UGI) development can help mitigate the climate, biodiversity, and habitat crises faced by cities and support the achievement of sustainable urban development. Based on the relevant data of 41 cities in the Yangtze River Delta region obtained from 2011 to 2020, this study measured the development level of natural and geographic conditions, economic development, urban construction, social and cultural development, and eco-environment quality and urban green infrastructure (UGI); evaluated the development trend of UGI in the region during the 12th Five-Year Plan and 13th Five-Year Plan by using entropy TOPSIS; and used fs/QCA to explain the high-level development path of each city toward the achievement of a green infrastructure. The results showed that (1) the development level of UGI in the Yangtze River Delta region decreases from southeast to northwest, and gradually decreases from Shanghai, Hangzhou, and other central cities. (2) There were several different configurations of high levels and non-high levels of UGI development drivers across regions, confirming the existence of multiple causality and asymmetry indices in the drivers of UGI. (3) During the "12th Five-Year Plan" and the "13th Five-Year Plan" period, the conditions needed to achieve a high level of UGI gradually became stricter, expanding from nature-social culture and urban construction-eco-environmental drivers to nature-urban construction, nature-social culture-eco-environmental, urban construction-economy-social culture-eco-environmental drivers. Research findings can provide greater guidance and implications for future sustainable urban development.

A new perspective on anthropogenic nitrogen loss mitigation strategies: Integrated control via sustainable regional integration

Unregulated regional integrated development disrupts the reactive nitrogen (Nr) cycle, adding complexity to anthropogenic Nr environmental losses. The objective of this study was to establish a framework for mitigating anthropogenic Nr loss through a new regional integration perspective by analyzing anthropogenic Nr loss and integrated control strategies in the Yangtze River Delta (YRD) region from 2011 to 2020. The results revealed that the total Nr loss in the YRD ranged from 1780.7 to 1972.0 Gg N yr-1. Re-linking cropland and livestock is crucial for reducing Nr loss, as they act as the main sources of Nr loss. Spatial analysis at the regional scale revealed that regional integration has led to a dispersion of Nr loss, while uneven development among cities has resulted in a westward shift of 8.6 km in the Nr loss centroid, suggesting the need for the implementation of collaborative governance and integrated environmental regulation in the YRD. At the city scale, 27 cities were clustered into six types based on the similarity of Nr loss structural characteristics, allowing for the development of targeted reduction policies based on the specific Nr structural characteristics of each city. The results of driver and mitigation potential analysis indicated the feasibility of achieving the shared goal of sustainable regional integration and the application of optimal mitigation strategies in different cities and the YRD. Overall, the new-perspective framework established in this study provides valuable references for sustainable Nr management in the context of regional integration.

The incentive effect of creating a national health city on the ecological welfare performance: based on the evidence of Yangtze River Delta in China

Under the background of China's high-quality development, improving the ecological environment, enhancing the welfare level of residents and promoting the sustainable development of cities have become a hot issue of widespread concern in society. This paper focuses on the Yangtze River Delta region, aiming to study the direct incentive effect and spatial spillover effect of creating a national health city on the ecological welfare performance. It also further decomposes the spatial spillover effect, to study the path of spatial spillover and the characteristics of heterogeneity in different regions. The results show that (1) the ecological welfare performance in the Yangtze River Delta is increasing year by year, and the average growth rate was 0.23%. There is a spatial effect of "beggar-thy-neighbor." The improvement of local ecological welfare performance will reduce the performance level of the surrounding areas by more than 30%. (2) To create a national health city in local areas, the ecological welfare performance in local areas will be increased by 0.087%, and the ecological welfare performance in the surrounding areas will be increased by 0.031%. Among them, the ecological welfare performance of the surrounding national health cities will be increased by 0.067%, and the ecological welfare performance of the surrounding non-health cities will not be significantly improved. (3) The effect has heterogeneity in coastal and inland areas. In terms of direct incentive effect, coastal areas are more obvious than inland areas. In terms of spatial spillover effect, inland areas show more positive spatial spillover effect than coastal areas, whether in groups or within groups. This paper is the first time to study this issue, enhance the theory, and practice of ecological welfare performance.

Governance matters: Urban expansion, environmental regulation, and PM2.5 pollution

Increasing PM2.5 pollution in urban expansion threatens citizens' health. Environmental regulation has proven to be an effective tool to directly combat PM2.5 pollution. However, whether it can moderate the impacts of urban expansion on PM2.5 pollution, in the context of rapid urbanization, is an interesting and unexplored topic. Therefore, this paper constructs a Drivers-Governance-Impacts framework and explores in depth the interactions among urban expansion, environmental regulation, and PM2.5 pollution. Based on 2005-2018 sample data from the Yangtze River Delta region, the estimation results of the Spatial Durbin model imply that (1) urban expansion has an inverse U-shaped association with PM2.5 pollution. The positive correlation may reverse when the ratio of urban built-up land area hits 0.21. (2) Of the three environmental regulations, investment in pollution control has little impact on PM2.5 pollution. Pollution charges and public attention exhibit a U-shaped and inverted U-shaped relationship with PM2.5 pollution, respectively. (3) In terms of moderating effects, pollution charges can exacerbate PM2.5 pollution from urban expansion, while public attention can inhibit it through its monitoring role. Therefore, we suggest that cities adopt differentiated strategies of urban expansion and environmental protection according to their urbanization levels. Meanwhile, appropriate formal regulation and strong informal regulation will help improve air quality.

Study on eco-efficiency of cultivated land utilization based on the improvement of ecosystem services and emergy analysis

Cultivated land is the result of the cooperation between humans and nature. The utilization of cultivated land hopes to realize a "win-win" situation of food production and ecological protection to promote sustainable development. Previous studies on the eco-efficiency of agro-ecosystem mainly considered material input, agricultural product output and environmental pollution, and did not systematically include the natural input and ecological product output, which had limitations on the study of sustainable development of cultivated land utilization. Therefore, this study initially used emergy analysis and ecosystem service assessment methods to include the natural input and ecosystem service output of cultivated land into the assessment framework of eco-efficiency of cultivated land utilization (ECLU) and used the Super-SBM model to calculate the ECLU in the Yangtze River Delta (YRD) region in China. In addition, we also discussed the influencing factors of ECLU by the OLS model. Here we show that the ECLU was lower in cities with higher agricultural intensive utilization in the YRD. And in cities with better ecological conditions, the ECLU value obtained based on our adjusted ECLU assessment framework was higher than the traditional agricultural eco-efficiency assessment, indicating that the assessment method in this study paid more attention to ecological protection in the application. In addition, we found that crop diversity, paddy/dry land ratio, cultivated land fragmentation and terrain are the factors affecting the ECLU. This study helps provide a scientific basis for decision-makers to improve the ecological function of cultivated land based on ensuring food security and furthermore promote regional sustainable development.

Spatio-Temporal Difference in Agricultural Eco-Efficiency and Its Influencing Factors Based on the SBM-Tobit Models in the Yangtze River Delta, China

In the Yangtze River Delta region, where the agricultural economy is well developed and agricultural pollution and carbon emissions are significant, a regional study of AEE (Agricultural Eco-Efficiency) is crucial to reducing agricultural environmental pollution, improving the rationalization of agricultural production layout, and promoting the realization of low-carbon goals. The SBM-Tobit model and GIS were employed to analyze AEE based on the carbon emission evaluation system in the spatial and temporal characteristics, as well as the influencing factors and the migration path of the center of gravity in the "low carbon" context. A rational plan of agricultural production was proposed according to the results. The following results were obtained: (1) The level of AEE in the Yangtze River Delta region was high, and the region exhibited a U-shaped curve change from 2000 to 2020, with a fluctuating decrease from 2000 to 2003 and a fluctuating increase from 2004 to 2020. The regional spatial development balance was enhanced, while there was a spatial incongruity in the development process of AEE enhancement, high in the southwest and low in the northeast; (2) AEE generally had a high regionalized agglomeration of low-low in the southwest and high-high in the northeast. Nonetheless, temporal heterogeneity was observed in spatial correlation, and the correlation weakened with time variation; (3) Urbanization level, agricultural production structure, crop cultivation structure, and fertilizer application intensity were the main factors influencing AEE in the Yangtze River Delta region; (4) The center of gravity of AEE in the Yangtze River Delta region shifted to the southwest under the influence of "low-carbon" related policies. Therefore, the improvement of AEE in the Yangtze River Delta region should focus on inter-regional coordination and linkages, rational planning of production factors, and the formulation of measures under relevant carbon policies.

Association between Dairy Consumption and Psychological Symptoms: Evidence from a Cross-Sectional Study of College Students in the Yangtze River Delta Region of China

BACKGROUND

Assessing the dairy consumption and psychological symptoms of Chinese college students as a reference for the mental health of Chinese college students.

METHODS

A three-stage stratified whole-group sampling method was used to investigate dairy consumption and psychological symptoms among 5904 (2554 male students, accounting for 43.3% of the sample) college students in the Yangtze River Delta region. The mean age of the subjects was 20.13 ± 1.24 years. Psychological symptoms were surveyed using the Brief Questionnaire for the Assessment of Adolescent Mental Health. The detection rates of emotional problems, behavioral symptoms, social adaptation difficulties and psychological symptoms among college students with different dairy consumption habits were analyzed using chi-square tests. The association between dairy consumption and psychological symptoms was assessed using a logistic regression model.

RESULTS

College students from the "Yangtze River Delta" region of China participated in the study, of which 1022 (17.31%) had psychological symptoms. The proportions of participants with dairy consumption of ≤2 times/week, 3-5 times/week, and ≥6 times/week were 25.68%, 42.09%, and 32.23%, respectively. Using dairy consumption ≥6 times/week as a reference, multifactor logistic regression analysis showed that college students with dairy consumption ≤2 times/week (OR = 1.42, 95% CI: 1.18, 1.71) were at higher risk of psychological symptoms (p < 0.001).

CONCLUSION

During the COVID-19 pandemic, Chinese college students with lower dairy consumption exhibited higher detection rates of psychological symptoms. Dairy consumption was negatively associated with the occurrence of psychological symptoms. Our study provides a basis for mental health education and increasing knowledge about nutrition among Chinese college students.

The Relationship between the Spatial and Temporal Evolution of Land Use Function and the Level of Economic and Social Development in the Yangtze River Delta

To explore the spatiotemporal evolution characteristics of land use function and its correlation with social and economic development levels, taking the Yangtze River Delta region as an example, we quantified the multifunctional land use in the Yangtze River Delta region from 2000 to 2020 on a 5 km × 5 km grid and analyzed its spatiotemporal evolution characteristics. Each city's comprehensive measure of economic development used the projection tracing method. Person's method of interpretation was used for correlation between the spatial and temporal evolution of land use functions and the level of economic development and its coupling association. The study shows that: (1) from 2000 to 2020, the agricultural production function > ecological function > living function > non-agricultural production function in the Yangtze River Delta, but the non-agricultural production and living functions were gradually increasing, while the agricultural production and ecological functions were decreasing. In terms of spatial distribution, the agricultural production function decreases significantly around the built-up area due to the expansion of the built-up area. The non-agricultural production function strengthened around the central city in a network pattern and had a path-locking effect. Topography limits life functions, with high north and low south partially overlapping with non-agricultural production functions. Furthermore, the ecological function was high in the south and low in the north and continues to weaken due to the interference of human activities. (2) The spatiotemporal heterogeneity of different functions generated trade-offs/synergies. The trade-off relationship was prominent in agricultural production and non-farm production function and living function, and non-farm production and living function and ecological function during the study period. Conversely, agricultural production and ecological functions and non-farm production and subsistence functions were generally synergistic. Spatially, there was substantial spatial heterogeneity in the trade-off/synergy relationship between the two functions. (3) There was a clear correlation and spatial coupling between land use function indices and economic development levels in the whole region and sample zones. Still, the dynamic and regional nature of the evolution of land use functions results in sudden changes and jumps in different functions in space. Therefore, in the future integration of the Yangtze River Delta, it is necessary to pay comprehensive attention to the morphology of different land use functions and their synergy/trade-off relationship and to adjust the spatial governance strategy promptly according to the local conditions and the situation.

The Influencing Effect of Tourism Economy on Green Development Efficiency in the Yangtze River Delta

In the context of ecological priority and green development strategy, accelerating the upgrading of tourism structure and promoting the development of ecotourism is an important guarantee to achieve green and low-carbon economic growth and high-quality development. On the basis of constructing comprehensive evaluation indicators of tourism development (TD) and green development efficiency (GDE), this study analyzed the impulse response relationship between TD and GDE and the impact effect of TD on GDE in the Yangtze River Delta region from 2000-2018. Findings showed that: (1) During the study period, TD generally exhibited a W-shaped fluctuating upward trend and GDE showed a staggered evolution of upward and downward fluctuations, while both regional gaps of TD and GDE continued to decrease. (2) Most cities had made a leap from low to medium, high, and higher levels of tourism development, with tourism development levels decreasing along the Yangtze River basin to the north and south of the delta. The overall green development efficiency was relatively low, showing a spatial pattern of high value in the southern delta and low value in the northwest delta. (3) There was a one-way Granger causality of TD on GDE, and the impact of TD on GDE showed a significant positive cumulative effect. (4) TD exhibited a significant inverted U-shaped impact on GDE. The economic development level and government intervention had a significant positive impact on GDE. The proportion of secondary industry, energy consumption intensity, and foreign direct investment had a significant negative driving effect on GDE. While the impact of environmental regulation on GDE was insignificant positive. This study has great practical significance to alleviate the problems of urban resources and environment, and to realize a green economy and high-quality life.

The Interaction Mechanism of Fiscal Pressure, Local Government Behavioral Preferences and Environmental Governance Efficiency: Evidence from the Yangtze River Delta Region of China

In environmental governance, local governments are the main actors, and their behavioral preferences between economic growth competition (EGC) and environmental regulation (ER) affect the inputs and outputs of environmental governance. Most studies discuss the relationship between government behaviors and the environment from the fiscal decentralization perspective, with few studies from the fiscal pressure (FP) perspective. Importantly, the bidirectional interaction mechanism is easily ignored. This study measured local government FP, EGC, ER, and environmental governance efficiency (EGE) in China's Yangtze River Delta (YRD) region from 2000 to 2020. Moran's I index was used to identify the change characteristics of local government behavioral preferences. The interaction mechanism was analyzed by a panel vector autoregression (PVAR) model. The results show that (1) from 2000 to 2020, FP was generally strengthened. EGE generally showed fluctuating and rising change characteristics, with more obvious fluctuating and rising characteristics before 2012 and after 2012, respectively. Local governments shifted from a strong alternative preference to a weak synergistic preference. (2) FP had a self-reinforcing effect. EGC and ER had a self-weakening effect. EGE had not only a self-weakening effect but also a weak self-dependence. (3) There is a double negative interaction mechanism between FP and local government behavioral preferences. FP made local governments prefer to reduce EGC and relax ER, but in fact, EGC and ER were conducive to alleviating FP. (4) There is a negative transitive influence mechanism between FP, local government behavioral preferences and EGE. The negative effect of FP on EGE can be transmitted by reducing EGC and ER. This paper provides a scientific basis for improving EGE in the YRD region and understanding the behavioral logic of local governments' environmental governance and a reference for other rapidly industrializing and urbanizing regions.

Co-effect assessment on regional air quality: A perspective of policies and measures with greenhouse gas reduction potential

Clean air policies have achieved remarkable air quality improvement in China for the last decade. However, as more importance was attached to climate issues and further improvement of air quality, policies with greenhouse gas (GHG) reduction potential were supposed to play a significant role. Here, we designed a conventional legislation pathway scenario (CLP) and an enhanced greenhouse gas reduction scenario (EGR), to estimate the co-effects of policies effective in GHG reduction on air pollutant control and air quality improvement in the Yangtze River Delta (YRD) region from 2014 to 2020, adopting a measure-specific evaluation method and an integrated WRF-CAMx model simulation. Results showed that: 1) With the implementation of enhanced measures with GHG reduction potential, emissions of SO₂, NO_x, PM_2.5, PM₁₀, VOC_s and NH₃ decreased by 16.4 %, 21.6 %, 18.6 %, 16.5 %, 23.9 % and 15.4 % in EGR scenario respectively, compared with CLP scenario. And the annual mean simulated concentrations of PM_2.5, SO₂ and NO₂ of the YRD decreased by 11.2 %, 15.4 % and 20.6 %, respectively. 2) The average 8-h maxima (MDA8) concentration of O₃ presented a slightly increasing trend under the impacts of measures with GHG reduction potential, which might be on account of the unbalanced control of NO_x and VOC_s, the two major precursors of O₃. 3) Based on the source apportionment analysis, major partition of total ozone in the four receptors in YRD was from regional transportation, rather than local formation. And the major sectors contributing to ozone were industry and transportation sector. This study quantitatively assessed the co-benefits of GHG-control-effective policies and specific measures on air quality improvement, which would help to provide implications for future policy-making to achieve air pollution and climate change co-control.

Impacts of COVID-19 pandemic on foreign trade intermodal transport accessibility: Evidence from the Yangtze River Delta region of mainland China

We address the problem of the impacts of COVID-19 pandemic on foreign trade transport by introducing a foreign trade intermodal transport accessibility (FTITA) index. First, we present the definition of FTITA, which combines the convenience of transporting domestic cargoes to overseas regions by an international intermodal transport network and the trade attractiveness of the domestic cargoes in the overseas regions. Second, we analyze the path choice behaviors of domestic shippers and propose the measurement method of the FTITA index. Finally, using the 41 cities in the Yangtze River Delta region in mainland China as origins and eight overseas regions as destinations, we empirically analyze the impacts of COVID-19 pandemic on the FTITA. With the empirical study conducted in the prepandemic and postpandemic years, we analyzed the overall trends of the FTITAs from the YRD region to eight overseas regions, spatial patterns of the distributions of the FTITAs in the YRD region, rankings of average FTITA values for the top ten cities in the YRD region, and the FTITAs for different cargoes. The results indicate that the FTITAs of the YRD region in the prepandemic year are significantly higher than those in the postpandemic year. Moreover, in both the prepandemic and postpandemic years, the FTITAs to North America, Japan/South Korea, Europe, and Southeast Asia are significantly higher than those to Oceania, Middle East, South America, and Africa. Through analysis of the spatial patterns of the FTITAs across cities in the YRD region, we find that the cities with high FTITA are mainly close to Shanghai Port and Ningbo Port; the cities with middle-high FTITA are mainly located in southern Zhejiang and the regions along the Yangtze River; the cities with middle-low FTITA are mainly located in northern Jiangsu; and the cities with low FTITA are located in northern Anhui. Furthermore, comparing the impacts of COVID-19 pandemic on the FTITAs for different cargoes, we observe that COVID-19 has the least impact on foodstuffs and event cargoes. Our findings can guide decision makers in implementing policies for alleviating the impacts of COVID-19 pandemic on foreign trade transport and further promoting the sustainable development of port and shipping industries.

Analysis of healthcare needs differences and influencing factors among elderly population: Evidence from Yangtze River Delta region, China

The quality of healthcare services is related to the quality of life of older people in their later years. A comprehensive evaluation of the healthcare needs of the elderly is the basic basis for providing targeted healthcare services for the elderly population. Taking the Yangtze River Delta region of China as an example, this article constructs an index system for evaluating the healthcare needs among the elderly, and explores the healthcare needs of the elderly and the influencing factors based on Dataset of the Fourth Sample Survey on the Living Conditions of China's Urban and Rural Older Persons. The study concludes that: Age 75 is the cut-off point for the healthcare needs of the elderly, with the growth of healthcare needs of the elderly aged 60-75 relatively flat and the growth of healthcare needs of the elderly aged 75 and above rising sharply. There is a wide variation in the Daily Activities Care Index, Incontinence Index and Aids Use Index scores and their indicators, as reflected in the differences in healthcare needs of older people in different age groups and in urban and rural areas. Healthcare needs of the elderly show a high positive correlation with the Daily Activities Care Index and Incontinence Index; healthcare needs of the elderly show a cubic function curve correlation with the assistive device use index. Community elderly healthcare services are conditions that influence the demand for elderly healthcare, but the low proportion of elderly people staying in elderly care institutions is due to a combination of low affordability, general quality of elderly care services and cultural factors. Educational attainment and marital status are micro-conditions that influence the demand for healthcare in old age. In terms of educational attainment, elderly people who have not attended school have an increasing need for healthcare as they get elderly. In terms of marriage, there is a strong negative correlation between the willingness to healthcare needs among elderly people with a spouse and a strong willingness to healthcare needs among elderly people who are widowed.

Spatiotemporal characterization of aerosols and trace gases over the Yangtze River Delta region, China: impact of trans-boundary pollution and meteorology

BACKGROUND

The spatiotemporal variation of observed trace gases (NO₂, SO₂, O₃) and particulate matter (PM_2.5, PM₁₀) were investigated over cities of Yangtze River Delta (YRD) region including Nanjing, Hefei, Shanghai and Hangzhou. Furthermore, the characteristics of different pollution episodes, i.e., haze events (visibility < 7 km, relative humidity < 80%, and PM_2.5 > 40 µg/m³) and complex pollution episodes (PM_2.5 > 35 µg/m³ and O₃ > 160 µg/m³) were studied over the cities of the YRD region. The impact of China clean air action plan on concentration of aerosols and trace gases is examined. The impacts of trans-boundary pollution and different meteorological conditions were also examined.

RESULTS

The highest annual mean concentrations of PM_2.5, PM₁₀, NO₂ and O₃ were found for 2019 over all the cities. The annual mean concentrations of PM_2.5, PM₁₀, and NO₂ showed continuous declines from 2019 to 2021 due to emission control measures and implementation of the Clean Air Action plan over all the cities of the YRD region. The annual mean O₃ levels showed a decline in 2020 over all the cities of YRD region, which is unprecedented since the beginning of the China's National environmental monitoring program since 2013. However, a slight increase in annual O₃ was observed in 2021. The highest overall means of PM_2.5, PM₁₀, SO₂, and NO₂ were observed over Hefei, whereas the highest O₃ levels were found in Nanjing. Despite the strict control measures, PM_2.5 and PM₁₀ concentrations exceeded the Grade-1 National Ambient Air Quality Standards (NAAQS) and WHO (World Health Organization) guidelines over all the cities of the YRD region. The number of haze days was higher in Hefei and Nanjing, whereas the complex pollution episodes or concurrent occurrence of O₃ and PM_2.5 pollution days were higher in Hangzhou and Shanghai.The in situ data for SO₂ and NO₂ showed strong correlation with Tropospheric Monitoring Instrument (TROPOMI) satellite data.

CONCLUSIONS

Despite the observed reductions in primary pollutants concentrations, the secondary pollutants formation is still a concern for major metropolises. The increase in temperature and lower relative humidity favors the accumulation of O₃, while low temperature, low wind speeds and lower relative humidity favor the accumulation of primary pollutants. This study depicts different air pollution problems for different cities inside a region. Therefore, there is a dire need to continuous monitoring and analysis of air quality parameters and design city-specific policies and action plans to effectively deal with the metropolitan pollution.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1186/s12302-022-00668-2.

Occurrence and risk assessment of volatile organic compounds in multiple drinking water sources in the Yangtze River Delta region, China

Volatile organic compounds (VOCs) are widely present in water environment, which can threaten ecological sustainability and human health. The concentrations of VOCs and their ecological risks in drinking water are of great concern to human beings. Therefore, 54 kinds of VOCs were investigated from 58 locations of the Yangtze River Delta Region (Yangtze River, Qiantang River, Huangpu River, Taihu Lake and Jiaxing Urban River). Out of 54 target compounds, only 31 VOCs were detected, with total concentrations ranging from 0.570 to 46.820 μg/L from 58 locations of all drinking water sources. Among all detected VOCs compounds, only toluene and styrene can cause high-level ecological risk at location TH-2 of Taihu Lake. According to the carcinogenic and non-carcinogenic risk index, compounds such as 1,2-dichloroethane, bromodichloromethane and 1,1,2-trichloroethane posed a higher carcinogenic risk, and 1,2-dichloroethane, trichloroethylene and toluene posed a higher non-carcinogenic risk. Olfactory risks of water bodies in the Yangtze River Delta region are negligible. Although the concentrations of VOCs in the Yangtze River Delta region did not exceed national standards in China and guidelines of the World Health Organization (WHO) for drinking water, the presence of some ecological and health risks indicated that future monitoring studies and control practices are important to ensure ecological safety of drinking water sources.

Self-adaptive bandwidth eigenvector spatial filtering model for estimating PM2.5 concentrations in the Yangtze River Delta region of China

PM_2.5 concentrations are commonly estimated using geographically weighted regression (GWR) models, but these models may suffer from multi-collinearity and over-focus on local feature problems. To overcome these shortcomings, a self-adaptive bandwidth eigenvector spatial filtering (SA-ESF) model utilizing the golden section search (GO-ESF) and genetic algorithm (GA-ESF) was proposed. The SA-ESF model was applied to estimate ground PM_2.5 concentrations in the Yangtze River Delta (YRD) region of China both seasonally and annually from December 2015 to November 2016 using remotely sensing data, factory locations, and road networks. The results of the original eigenvector spatial filtering (ESF), GO-ESF, GA-ESF, and GWR models show that the GA-ESF model offers better performance and exhibits a better average adjusted R² which is 26.6%, 15.3%, and 10.8% higher than for the ESF, GO-ESF, and GWR models, respectively. We next calculated stochastic site indicators that can describe characteristics of regional concentration from interpolated concentration maps derived from the GA-ESF and GWR models. The concentration maps and stochastic site indicators point to major differences in the PM_2.5 concentrations in mountainous areas. There are notably high concentrations in those areas using the GWR model, in contrast with the GA-ESF results, indicating that there may be overfitting problems using the GWR model. Overall, the proposed SA-ESF model with the genetic algorithm technique can capture both global and local features and achieve promising results.

Cultivation of Entrepreneurial Psychology and Innovation Ability by New Media Art Under the Reform of Publishing Industry

In order to optimize the resource allocation of the traditional publishing industry in the new media era, it is proposed to integrate the traditional publishing and digital publishing industries to solve the problem of unbalanced resource distribution under dual-track conditions. Professional talents with innovative entrepreneurial ability and psychology in colleges and universities are cultivated to promote the integration and reform process of the publishing industry under the background of new media art. First, the study analyzes the digital reform issues facing the development of the publishing industry in the new media era. Second, in view of the development situation of the publishing industry in the Yangtze River Delta, it is proposed to establish a development model of integrated publishing in the Yangtze River Delta through resource allocation. Then, under the new media art form, the teaching mode of creative and entrepreneurial talents training in art colleges and universities is optimized to cultivate students’ innovative ability and entrepreneurial positive psychology. The research results show that the number of books printed in Shanghai in the Yangtze River Delta is 13,000 types per year, and the number is still rising; however, periodicals and newspapers are affected by the new media industry, and the number of publications is declining. The printing volume has dropped by 50% in 9years; the questionnaire survey results show that 68% of the students are very interested in entrepreneurial activities, but 53% of the students have not carried out entrepreneurial activities at all, indicating that the students’ entrepreneurial ability is insufficient. The results provide a reference for studying the reform direction of the publishing industry and cultivating entrepreneurial talents in the context of new media.

[Emission Inventory of Intermediate Volatility Organic Compounds(IVOCs) from Biomass Burning in the Yangtze River Delta During 2010-2018]

Intermediate volatility organic compounds (IVOCs) are important precursors of secondary organic aerosols (SOA) but are currently not included in the conventional emissions inventories. Biomass burning represents an important source of IVOCs that could contribute to SOA formation. This study estimated the IVOC emissions from biomass burning in the Yangtze River Delta (YRD) region from 2010 to 2018 based on the fire inventory from NCAR (FINN) and the IVOCs/primary organic aerosol (POA) ratio reported in literature. During this period, the total number of fire events over the YRD region presented a declining trend, with an average of 10⁴ fire events detected per year. During 2016-2018, the average number of fire events was approximately 6000 per year, which was 60% less than that prior to 2016. In terms of the monthly variation, the period from May to August was the period with the most fires observed, which was followed by a small peak in October. The results calculated based on the IVOCs/POA ratio method showed that the IVOC emissions from biomass burning exhibited large differences with different combinations of POA/OC and IVOCs/POA ratios, ranging from a maximum of 305.7×10⁴ t to as small as 10.5×10⁴ t. Monte Carlo simulation revealed that the uncertainties associated with the IVOCs/POA ratio method range from -99% to 68%.

Characterization of vertical distribution and radiative forcing of ambient aerosol over the Yangtze River Delta during 2013-2015

As the central part of eastern China, the Yangtze River Delta (YRD) region, with its rapid economic growth and industrial expansion, has experienced severe air quality issues. In this study, the monthly variation and interaction between aerosol direct radiative forcing (ADRF) and aerosol vertical structure during 2013-2015 over the YRD were investigated using ground-based observations from a Micro Pulse Lidar (MPL) and a CE-318 sun-photometer. Combining satellite products from MODIS and CALIPSO, and reanalysis wind fields, an integrated discussion of a biomass burning episode in Hangzhou during August 2015 was conducted by applying analysis of optical properties, planetary boundary layer (PBL), spatial-temporal and vertical distributions, backward trajectories, Potential Source Contribution Function (PSCF), and Concentration Weighted Trajectory (CWT). The results reveal that a shallower PBL coincides with higher scattering extinction at low altitude, resulting in less heating to the atmosphere and radiative forcing to the surface, which in turn further depresses the PBL. In months with a deeper PBL, the extinction coefficient decreases rapidly with altitude, showing stronger atmospheric heating effects and ADRF to the surface, facilitating the turbulence and vertical diffusion of aerosol particles, which further reduces the extinction and raises the PBL. Because of the hygroscopic growth facilitated by high relative humidity, June stands out for its high scattering extinction coefficient and relatively low PBL, and the reduced ADRF at the surface and the enhanced cooling effect on near-surface layer in turn depresses the PBL. Absorptive aerosols transported from biomass burning events located in Zhejiang, Jiangxi, and Taiwan provinces at 1.5 km, result in high ADRF efficiency for atmospheric heating. And the enhanced heating effect on near-surface layer caused by absorptive particles facilitates PBL development in August over the YRD.

An improved gridded polycyclic aromatic hydrocarbon emission inventory for the lower reaches of the Yangtze River Delta region from 2001 to 2015 using satellite data

An improved gridded polycyclic aromatic hydrocarbon (PAH) emission inventory for the lower reaches of the Yangtze River Delta (YRD) region from 2001 to 2015 was developed using satellite data. Despite rapid increases in energy consumption, the annual total emissions of the 16 PAHs showed overall decreasing trends, from a maximum of 5445 t in 2001 to a minimum of 2619 t in 2015, with the largest decline (84.6%) observed in the residential sector. Different spatial allocation methods used in gridded PAH emission inventories have substantial influences on the distributions of PAHs; therefore, we improved the accuracy of the spatial allocation of industrial and open biomass burning PAH emissions using various satellite data. The gridded secondary and tertiary industrial GDP (GDP₂₃) calculated using corrected nighttime light data was the best spatial proxy for the spatial allocation of industrial PAH emissions in the YRD region. We generated a gridded burned area for 2001-2015 by coupling the MCD64A1 and MCD14ML fire products, which was used to allocate PAH emissions from open biomass burning. Finally, we found that changes in the spatial distribution of PAH emissions were mainly driven by energy consumption and degree of technological advancement in different regions during 2001-2015.

[VOCs Characteristics and Sources Apportionment in Yixing City During the G20 Summit]

A continuous measurement was conducted in Yixing city urban area from 24^th August to 15^th September using TH-300B continuous online GC-MS instrument during G20 summit in Hangzhou, 2016. The VOCs average mass concentrations of alkane, alkene, aromatic, acetylene, haloalkane hydrocarbons, OVOC and acetonitrile were 11.00×10^-9, 1.93×10^-9, 5.78×10^-9, 1.23×10^-9, 4.16×10^-9, 10.37×10^-9, 0.27×10^-9, respectively. The photochemical reaction activity was calculated by using the maximum potential coefficient of Ozone Formation Potential. Alkene and aromatic hydrocarbons were the most active components of OFP. By applying the positive matrix factorization(PMF)model, five major factors were extracted to identify the sources of NMHCs in Yixing city, including industry(42.2%),vehicle exhaust(17.9%), fuel evaporation(20.8%), paint/solvent usage(7.0%)and plant(12.1%). Combined with the conditional probability function(CPF) analysis, source of anthropogenic pollution was related to the distribution of industrial enterprises in the northwest and southeast, while the plant source was related to the forest hilly region of Southwest Yixing city. The effect of air pollutant emission reduction showed that the primary emission air pollutants had declined significantly during the strict control period from 1^th to 6^th September in G20 summit,2016, and the industry proportion was reduced to 30.5%, whereas the plant proportion increased to 16.8%.

Contamination and health risk assessment of PAHs in soils and crops in industrial areas of the Yangtze River Delta region, China

This is the first investigation into both soil and crop contamination and associated health risks by polycyclic aromatic hydrocarbons (PAHs) in industrial areas of the Yangtze River Delta region (YRDR). Soil and crop samples were collected from farmland surrounded by three typical industries (a steelworks [SW], a petrochemical facility [PF] and a power plant [PP]), and the concentrations and health risks of PAHs in soils and crops were evaluated. The average concentrations of 16 USEPA priority PAHs in surface soil and subsoil were 471.30 μg kg^-1 and 341.40 μg kg^-1, respectively. The respective average concentrations of 16 PAHs in amaranth, spinach, Chinese chive, and rice tissues were 1710.49, 1176.96, 1218.36 and 352.12 μg kg^-1. Based on both the results of a principal component analysis (PCA) and the PAH ratios, the main sources of the PAHs in soils were determined to be the combustion of coal and petroleum. The total values of incremental lifetime cancer risk (ILCR) for males induced by both soils and crops were 2.19 × 10^-4, 2.53 × 10^-4, and 9.17 × 10^-4, and for females were 2.21 × 10^-4, 2.50 × 10^-4, and 9.68 × 10^-4 for childhood, adolescence, and adulthood, respectively. Soils contaminated with PAHs posed a lower risk than crops, but the ILCR values, 4.40 × 10^-5 and 3.82 × 10^-5 for males and females, was still much higher than the baseline value. The results of this investigation provide novel information for contamination evaluation and human health risk assessment in PAH-contaminated sites.