Spatiotemporal evolution patterns of ecosystem health in the Middle Reaches of the Yangtze River Urban Agglomerations

Urban agglomerations have gradually formed in different Chinese cities, exerting great pressure on the ecological environment. Ecosystem health is an important index for the evaluation of the sustainable development of cities, but it has rarely been used for urban agglomerations. In this study, the ecosystem health in the middle reaches of the Yangtze River Urban Agglomeration was assessed using the ecosystem vigor, organization, resilience, and services framework at the county scale. A GeoDetector was used to determine the effects of seven factors on ecosystem health. The results show that: (1) The spatial distribution of ecosystem health differs significantly. The ecosystem health in the centers of Wuhan Metropolis, Changsha–Zhuzhou–Xiangtan City Group, and Poyang Lake City Group is significantly lower than in surrounding areas. (2) Temporally, well-level research units improve gradually; research units with relatively weak levels remain relatively stable. (3) The land use degree is the main factor affecting ecosystem health, with interactions between the different factors. The effects of these factors on ecosystem health are enhanced or nonlinear; (4) The effect of the proportion of construction land on ecosystem health increases over time. The layout used in urban land use planning significantly affects ecosystem health.

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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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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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Emergy-based urban ecosystem health evaluation of the Yangtze River Delta urban cluster in China

Procedia Environmental Sciences ◽

10.1016/j.proenv.2010.10.078 ◽

2010 ◽

Vol 2 ◽

pp. 689-695 ◽

Cited By ~ 3

Author(s):

Meirong Su

Keyword(s):

Yangtze River ◽

Ecosystem Health ◽

Urban Ecosystem ◽

Yangtze River Delta ◽

River Delta ◽

Health Evaluation ◽

The Yangtze River ◽

Urban Cluster ◽

Urban Ecosystem Health ◽

The Yangtze River Delta

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Effects of Land Use/Cover Change On Atmospheric Humidity in Three Urban Agglomerations in The Yangtze River Economic

10.21203/rs.3.rs-659431/v1 ◽

2021 ◽

Author(s):

Baoni Li ◽

Lihua Xiong ◽

Quan Zhang ◽

Shilei Chen ◽

Han Yang ◽

...

Keyword(s):

Land Use ◽

Air Temperature ◽

Land Surface ◽

Yangtze River ◽

Urban Expansion ◽

Regional Climate ◽

Urban Land ◽

The Yangtze River ◽

Atmospheric Humidity ◽

Urban Agglomerations

Abstract Land use/cover change (LUCC) affects regional climate not only through its direct changes of land surface properties, but also through its further modifications of land-atmosphere interactions. Urban land expansion is a typical case of LUCC in highly populated areas, and has been widely discussed about its impacts on regional air temperature, notably known as urban heat island (UHI) effects. Besides air temperature, atmospheric humidity, as another key variable in hydrometeorology and climate, would be inevitably affected by LUCC as well. However, the impacts of LUCC on atmospheric humidity seem to have not been investigated as much as on temperature. We examined atmospheric humidity changes by trend analyses of humidity indicators in three representative urban agglomerations in the Yangtze River Economic Belt (YREB), China during 1965-2017, and found the evident urban dry island (UDI) effects which are characterized by significant humidity decrease and vapor pressure deficit increase. In different urban cores, the severity levels of UDI are different. Furthermore, strong positive correlations between humidity and evapotranspiration, and between evapotranspiration and leaf area were detected during 2001-2017 when cities entered the accelerated stage of land expansion, indicating that LUCC affects regional climate through an ecohydrological way. We speculated that the UDI effect will not appear until urban land expands to a certain scale. Besides, the UHI effect emerged in the early stage of urban expansion, about 5 years earlier than the UDI effect, and has not performed prominently in recent years. This implies that urbanization-induced LUCC may exert a larger influence on UDI than on UHI in the current later period of urban expansion.

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Measuring Multi-Faceted Land Use Efficiency of Large-Scale Urban Agglomerations under Multi-Scale Drivers: Evidence from China

Land ◽

10.3390/land11010091 ◽

2022 ◽

Vol 11 (1) ◽

pp. 91

Author(s):

Jinfeng Ma ◽

Weifeng Li ◽

Zhao Wang ◽

Liang He ◽

Lijian Han

Keyword(s):

Land Use ◽

Yangtze River ◽

Yangtze River Delta ◽

River Delta ◽

The Yangtze River ◽

Construction Land ◽

Urban Agglomerations ◽

Land Use Efficiency ◽

Use Efficiency ◽

The Yangtze River Delta

Although urban agglomerations are vital sites for national economic development, comprehensive multidimensional investigations of their performance are lacking. Accordingly, we examined land use efficiency from multiple perspectives in two of the earliest developed and most advanced urban agglomerations in China, the Beijing–Tianjin–Hebei (BTH) region and the Yangtze River Delta (YRD), using different metrics, including trans-regional drivers of the spatial allocation of construction land. We found that: (1) The land use efficiency of urban agglomerations was context dependent. Whereas it was higher in the Beijing–Tianjin–Hebei region for population density per unit area of construction land than in the Yangtze River Delta region, the opposite was true for gross domestic production. Thus, a single aspect did not fully reflect the land use efficiency of urban agglomerations. (2) The land use efficiency of the two urban agglomerations was also scale dependent, and in the Yangtze River Delta region, the use of multiple metrics induced variations between aggregate and local measures. Median values for the land use efficiency of cities within an urban agglomeration were the most representative for comparative purposes. (3) The drivers of the spatial allocation of construction land were trans-regional. At the regional scale, most topographical factors were restrictive. Major regional transport networks significantly influenced the occurrence of construction land near them. Dominant cities and urban areas within each city exerted remote effects on non-dominant cities and rural areas. In principle, the median value can be considered a promising metric for assessing an urban agglomeration’s performance. We suggest that stringent management of land use in areas located along regional rail tracks/roadways may promote sustainable land use.

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The Effect of the Grain for Green Program on Ecosystem Health in the Upper Reaches of the Yangtze River Basin: A Case Study of Eastern Sichuan, China

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16122112 ◽

2019 ◽

Vol 16 (12) ◽

pp. 2112 ◽

Cited By ~ 1

Author(s):

Rui Han ◽

Luo Guo ◽

NuanYin Xu ◽

Dan Wang

Keyword(s):

Land Use ◽

River Basin ◽

Yangtze River ◽

Ecosystem Health ◽

Yangtze River Basin ◽

Vegetation Coverage ◽

The Yangtze River ◽

Grain For Green ◽

The Yangtze River Basin ◽

Eastern Sichuan

The Eastern Sichuan Region (ESR) is one of the key pilot regions for Grain for Green Program (GGP) implementation in the upper reaches of the Yangtze River basin in China. Therefore, monitoring the effect of the GGP on the ecosystem in the ESR is important. In this study, the Mann–Kendall Trend Test Model was used to ascertain the changes in vegetation coverage. The transfer matrix was used to explore the changes in Land Use/Land Cover (LULC). LULC change direction model (LCDM) was used to preliminarily assess the impact of LULC changes on the ecosystem. The Pressure–State–Response model (PSR), reflecting the human pressure and the ecosystem state, was applied to analyze the spatial–temporal characteristics of the ecosystem health index (EHI). The time span of this study was from 1990 to 2015. The results show that the vegetation coverage changed significantly (p < 0.05), and ecosystem function developed towards positive because of the increase in the coverage of forestland and water land and decrease in the coverage of farmland. The spatial distribution of the EHI was influenced by the pattern of land use. The eastern region, associated with a large area of forestland and grassland, has a low population density and a low degree of land use exploitation, resulting in a high EHI value. The situation was completely opposite in the western region. Regarding the temporal scale, in spite of the decreasing pressure indicator, most counties had experienced an increase in the EHI. There was a clear correlation between the increased EHI values and the restored areas at the third stage (2000–2005) (p < 0.05, r2 = 0.164), but this correlation disappeared at the latter stage (2005–2015) (p > 0.05). The changes showed significant variations in time and area because of differences in the process and the intensity of the implication of the GGP.

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