Spatiotemporal heterogeneity and driving factors of PM2.5 reduction efficiency: An empirical analysis of three urban agglomerations in the Yangtze River Economic Belt, China

The vulnerability of ecological environment threatens social and economic development. Recent studies failed to reveal the driving mechanism behind it, and there is little analysis on the spatial clustering characteristics of the vulnerability of urban agglomerations. Therefore, this article estimates ecological environment vulnerability in 2005, 2011, and 2017, determines Moran Index (MI) with spatial autocorrelation model, analyzes the spatial-temporal difference characteristics of ecological environment vulnerability of Yangtze River Urban Agglomeration and the spatial aggregation effect, and discusses its driving factors. The study results estimate that the overall vulnerability index of the Yangtze River Urban Agglomeration is in a mild fragile state. However, most fragile and slightly fragile cities are developing in the direction of moderate to severe vulnerability. The spatial agglomeration effect of the ecological environment vulnerability of the Yangtze River Urban Agglomeration is not obvious, and the effect of mutual ecological environment influence among cities is not obvious. Moreover, the driving factors of ecological environment vulnerability of Yangtze River city group changed from natural factors to social economic factors and then to policy factors. It is necessary to develop an ecological economy, coordinate the spatial agglomeration of urban agglomerations, and make balance the internal differences of urban agglomerations.

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Spatio-Temporal Coupling Characteristics and the Driving Mechanism of Population-Land-Industry Urbanization in the Yangtze River Economic Belt

Land ◽

10.3390/land10040400 ◽

2021 ◽

Vol 10 (4) ◽

pp. 400

Author(s):

Liejia Huang ◽

Peng Yang ◽

Boqing Zhang ◽

Weiyan Hu

Keyword(s):

Economic Development ◽

Spatial Correlation ◽

Yangtze River ◽

Three Dimensional ◽

Driving Mechanism ◽

The Yangtze River ◽

Central Cities ◽

Urban Agglomerations ◽

Development Level ◽

Coordination Degree

The purpose of this paper is to probe into the coupled coordination of urbanization in population, land, and industry to improve urbanization quality. A coupled coordination degree model, spatial analysis method and spatial metering model are employed. The study area is 110 prefecture-level cities in the Yangtze River Economic Belt. The study shows that: (1) the coupling degree of the population-land-industry urbanization grew very slowly between 2006 and 2016. On the whole, the three-dimensional urbanization is in a running-in period, and land-based urbanization dominates, while population-based urbanization and industry-based urbanization are relatively lagging behind. (2) The three major urban agglomerations, the Chengdu-Chongqing, the middle reaches of the Yangtze River and the Yangtze River Delta, are parallel to the whole area in terms of the coupling degree of the three dimensional urbanization with a well-ordered structure, especially in the central cities of the three major urban agglomerations. (3) There is significant spatial correlation in the coupling degree and coordination degree of the three-dimensional urbanization. The high value of coupling degree and coordination degree are clustered continuously in developed cities, provincial capitals, and central cities of the downstream reaches of the Yangtze River. (4) The coordinated degree has significant positive spatial autocorrelation, showing obvious spatial agglomeration characteristics: H-H agglomeration areas are concentrated in the downstream developed areas such as Jiangsu, Zhejiang, and Shanghai. L-L agglomeration areas are mainly concentrated in upstream undeveloped areas, but the number of their cities shows a decreasing trend. (5) The coordination degree of the three-dimensional urbanization is the result of the comprehensive effect of economic development level, the government’s decision-making behavior, and urban location. Among them, the economic development level, urbanization investment, traffic condition, and urban geographical location play a decisive role. This paper contributes to the existing literatures by exploring urbanization quality, spatial correlation and influencing factors from the perspectives of the three-dimensional urbanization in the Yangtze River Economic Belt. The conclusion might be helpful to promote the coupling and coordinated development of urbanization in population-land-industry, and ultimately to improve urbanization quality in the Yangtze River Economic Belt.

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Spatiotemporal Distribution Characteristics and Driving Forces of PM2.5 in Three Urban Agglomerations of the Yangtze River Economic Belt

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18052222 ◽

2021 ◽

Vol 18 (5) ◽

pp. 2222

Author(s):

Jin-Wei Yan ◽

Fei Tao ◽

Shuai-Qian Zhang ◽

Shuang Lin ◽

Tong Zhou

Keyword(s):

Geographically Weighted Regression ◽

Yangtze River ◽

National Level ◽

National Development ◽

Urban Agglomeration ◽

Spatiotemporal Distribution ◽

Weighted Regression ◽

Series Data ◽

The Yangtze River ◽

Urban Agglomerations

As part of one of the five major national development strategies, the Yangtze River Economic Belt (YREB), including the three national-level urban agglomerations (the Cheng-Yu urban agglomeration (CY-UA), the Yangtze River Middle-Reach urban agglomeration (YRMR-UA), and the Yangtze River Delta urban agglomeration (YRD-UA)), plays an important role in China’s urban development and economic construction. However, the rapid economic growth of the past decades has caused frequent regional air pollution incidents, as indicated by high levels of fine particulate matter (PM2.5). Therefore, a driving force factor analysis based on the PM2.5 of the whole area would provide more information. This paper focuses on the three urban agglomerations in the YREB and uses exploratory data analysis and geostatistics methods to describe the spatiotemporal distribution patterns of air quality based on long-term PM2.5 series data from 2015 to 2018. First, the main driving factor of the spatial stratified heterogeneity of PM2.5 was determined through the Geodetector model, and then the influence mechanism of the factors with strong explanatory power was extrapolated using the Multiscale Geographically Weighted Regression (MGWR) models. The results showed that the number of enterprises, social public vehicles, total precipitation, wind speed, and green coverage in the built-up area had the most significant impacts on the distribution of PM2.5. The regression by MGWR was found to be more efficient than that by traditional Geographically Weighted Regression (GWR), further showing that the main factors varied significantly among the three urban agglomerations in affecting the special and temporal features.

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The Evolution of the Urban Spatial Pattern in the Yangtze River Economic Belt: Based on Multi-Source Remote Sensing Data

Sustainability ◽

10.3390/su10082733 ◽

2018 ◽

Vol 10 (8) ◽

pp. 2733 ◽

Cited By ~ 8

Author(s):

Yang Li ◽

Hua Shao ◽

Nan Jiang ◽

Ge Shi ◽

Xin Cheng

Keyword(s):

Size Distribution ◽

Urban Areas ◽

Yangtze River ◽

Size Structure ◽

Urban Land ◽

Urban Agglomeration ◽

Spatial Distance ◽

The Yangtze River ◽

Urban Agglomerations ◽

Urban Size

The development of the Yangtze River Economic Belt (YREB) is an important national regional development strategy and a strategic engineering development system. In this study, the evolution of urban spatial patterns in the YREB from 1990 to 2010 was mapped using the nighttime stable light (NSL) data, multi-temporal urban land products, and multiple sources of geographic data by using the rank-size distribution and the Gini coefficient method. Through statistical results, we found that urban land takes on the feature of “high in the east and low in the west”. The study area included cities of different development stages and sizes. The nighttime light increased in most cities from 1992 to 2010, and the rate assumed an obvious growth tendency in the three urban agglomerations in the YREB. The results revealed that the urban size distribution of the YREB is relatively dispersed, the speed of urban development is unequal, and the trend of urban size structure shows a decentralized distribution pattern that has continuously strengthened from 1990 to 2010. Affected by factors such as geographical conditions, spatial distance, and development stage, the lower reaches of the Yangtze River have developed rapidly, the upper and middle reaches have developed large cities, and a contiguous development trend is not obvious. The evolution of urban agglomerations in the region presents a variety of spatial development characteristics. Jiangsu, Zhejiang, and Shanghai have entered a phase of urban continuation, forming a more mature interregional urban agglomeration, while the YREB inland urban agglomerations are in suburbanization and multi-centered urban areas. At this stage, the conditions for the formation of transregional urban agglomerations do not yet exist, and there are many uncertainties in the boundary and spatial structure of each urban agglomeration.

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Spatiotemporal Heterogeneity Analysis of Air Quality in the Yangtze River Delta, China

Sustainable Cities and Society ◽

10.1016/j.scs.2021.103603 ◽

2021 ◽

pp. 103603

Author(s):

Lizhi Miao ◽

Chengliang Liu ◽

Xin Yang ◽

Mei-Po Kwan ◽

Kai Zhang

Keyword(s):

Air Quality ◽

Yangtze River ◽

Yangtze River Delta ◽

River Delta ◽

The Yangtze River ◽

Heterogeneity Analysis ◽

Spatiotemporal Heterogeneity ◽

The Yangtze River Delta

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Spatial-Temporal Characteristics and Driving Factors of Coordination Degree of Ecological Efficiency and Industrial Structure Upgrading in the Yangtze River Economic Belt

Proceedings of the 2020 International Conference on Resource Sustainability: Sustainable Urbanisation in the BRI Era (icRS Urbanisation 2020) - Environmental Science and Engineering ◽

10.1007/978-981-15-9605-6_22 ◽

2020 ◽

pp. 311-324

Author(s):

Aoxiang Zhang

Keyword(s):

Yangtze River ◽

Industrial Structure ◽

Driving Factors ◽

The Yangtze River ◽

Ecological Efficiency ◽

Temporal Characteristics ◽

Coordination Degree ◽

Industrial Structure Upgrading

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Integrating Sustainability Assessment into Decoupling Analysis: A Focus on the Yangtze River Delta Urban Agglomerations

Sustainability ◽

10.3390/su12197872 ◽

2020 ◽

Vol 12 (19) ◽

pp. 7872

Author(s):

Yijia Huang ◽

Jiaqi Zhang ◽

Jinqun Wu

Keyword(s):

Environmental Sustainability ◽

Yangtze River ◽

Sustainability Assessment ◽

Yangtze River Delta ◽

River Delta ◽

The Yangtze River ◽

Urban Agglomerations ◽

Decoupling Analysis ◽

The Yrd ◽

The Yangtze River Delta

Rapid urbanization has led to a growing number of environmental challenges in large parts of China, where the Yangtze River Delta (YRD) urban agglomerations serve as a typical example. To evaluate the relationship between environmental sustainability gaps and urbanization in 26 cities of the YRD, this study revisited the environmental sustainability assessment (ESA) by combining the metrics of environmental footprints and planetary boundaries at the city level, and then integrated the footprint-boundary ESA framework into decoupling analysis. The results demonstrated considerable spatiotemporal heterogeneity in the environmental sustainability of water use, land use, carbon emissions, nitrogen emissions, phosphorus emissions and PM2.5 emissions across the YRD cities during the study period 2007–2017. Decoupling analysis revealed a positive sign that more than half of the 26 cities had achieved the decoupling of each category of environmental sustainability gaps from urbanization since 2014, especially for nitrogen and phosphorus emissions. On the basis of ESA and decoupling analysis, all the cities were categorized into six patterns, for which the optimal pathways towards sustainable development were discussed in depth. Our study will assist policy makers in formulating more tangible and differentiated policies to achieve decoupling between environmental sustainability gaps and urbanization.

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Driving Factors and Dynamics of Phytoplankton Community and Functional Groups in an Estuary Reservoir in the Yangtze River, China

Water ◽

10.3390/w11061184 ◽

2019 ◽

Vol 11 (6) ◽

pp. 1184 ◽

Cited By ~ 3

Author(s):

Changtao Yang ◽

Jing Nan ◽

Jianhua Li

Keyword(s):

Water Temperature ◽

Functional Groups ◽

Yangtze River ◽

Light Availability ◽

Ecological Status ◽

Water Source ◽

Driving Factors ◽

Nutrient Concentrations ◽

Drinking Water Source ◽

The Yangtze River

Qingcaosha Reservoir, an estuary reservoir on the Yangtze River and a drinking water source, is facing phytoplankton blooms and the factors driving changes in phytoplankton composition and distribution have not been well understood so far. To facilitate the understanding of this problem, we collected surface water samples from January to December 2014 monthly at 12 sampling sites. A total of 205 taxa classified into eight major taxonomic groups were identified. Cyclotella meneghiniana, Melosira varians, Melosira granulata, Cryptomonas ovata and Chlorella vulgaris were the species dominating at least one season. The long stratification period and high nutrient concentration resulted in high chlorophyll a concentration (36.1 ± 18.5 μg L−1) in the midstream and downstream during summer, and mass phytoplankton growth and sedimentation process led to nutrients decrease. In the reservoir, neither P or N limitation was observed in the study period. We observed that water temperature, nutrient concentrations and light availability (Zeu/Zmix) are critical in selecting functional groups. These results highlight that the functional groups characterized the water body well and showed a good ecological status based on the assemblage index (Q average = 4.0). This work also highlights that mixing regime, water temperature and light availability were the driving factors that determine phytoplankton dynamics.

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