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

2018 ◽  
Vol 10 (8) ◽  
pp. 2733 ◽  
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.

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

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.

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

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.

Urban dry island effect and its potential underlying mechanisms in the Yangtze River Delta urban agglomeration, China

2020 ◽  
Author(s):  
Baoni Li
Keyword(s):  
Yangtze River ◽  
Regional Climate ◽  
Yangtze River Delta ◽  
Urban Land ◽  
River Delta ◽  
Urban Agglomeration ◽  
The Yangtze River ◽  
Atmospheric Humidity ◽  
Urban Land Expansion ◽  
The Yangtze River Delta

<p>Land use/cover change (LUCC) affects regional climate change not only through its direct changes of land surface properties, but also through its further modifications of land-atmosphere interactions including the surface energy budget, water cycle and carbon cycle. Urban land expansion as a typical case of LUCC, has been widely discussed about its effects on regional climate, notably on temperature and known for urban heat island (UHI). Another important climate variable atmospheric humidity is also seriously affected by LUCC but has not earned as much attention as temperature. We examined atmospheric humidity changes by a series of indicators in the Yangtze River Delta urban agglomeration of China during 1965-2017, and found obvious urban dry land (UDI) effect in the urban cores, as characterized by decreased humidity and increased vapor pressure deficit. Furthermore, we found similar spatial patterns of humidity changes with urban land expansion process and strong correlations of humidity changes with evapotranspiration and leaf area index changes, indicating that LUCC affects regional climate through an ecohydrological way. We suggest that the UDI effect should be paid more attention in future urban planning and landscape design and more quantitative estimations of urban expansion effect on regional and global drying trends are needed.</p>

scholarly journals Research on the Dynamics and Evolution of Regional Blue-green Space Driven by the Development of World-class Urban Agglomerations

2021 ◽  
Author(s):  
Ziwu Pan ◽  
Jun Zhu ◽  
Zhenzhen Liu ◽  
Fen Qin
Keyword(s):  
Yangtze River ◽  
Green Space ◽  
Yangtze River Delta ◽  
River Delta ◽  
Urban Agglomeration ◽  
Heat Island ◽  
The Yangtze River ◽  
Urban Agglomerations ◽  
Island Effect ◽  
The Yangtze River Delta

Abstract In recent years, the process of urbanization in China has accelerated, and changes in the underlying surface have caused the difference in average temperature between built-up areas and suburbs to increase, resulting in an urban heat island effect, which has become an important environmental issue for today's urban sustainable development. The Yangtze River Delta urban agglomeration region is the fastest-growing region in China, with economically developed and populous cities such as Shanghai, Nanjing and Suzhou. It has become one of the six major urban agglomerations in the world, and its heat island effect is particularly prominent. The single urban heat island phenomenon gradually evolves into the urban agglomeration heat island phenomenon with urbanization. However, the dynamic transfer process of key blue-green space landscapes that can alleviate land surface temperature (LST) and regional thermal environment (RTE) is still poorly understood, especially in the context of urban agglomerations. With the approval of the State Council on the development plan of the Huaihe River Ecological Economic Belt, the construction of which has been officially upgraded to a national strategy. The Eastern HaiJiang River and Lake Linkage Zone (EJRLLZ) emphasizes strengthening the docking and interaction with the surrounding areas such as the Yangtze River Delta and the Wanjiang City Belt. With the diffusion of the heat island effect of the Yangtze River Delta urban agglomeration, as one of the areas with great potential development around the world-class urban agglomeration, the rich water body and green space in the ERLLZ area are also destroyed and affected. Therefore, we take this region as a case to further quantify the impact of urbanization and urban agglomeration development on the dynamics and evolution of blue-green space.

scholarly journals Assessing Ecosystem Services Supply-Demand (Mis)Matches for Differential City Management in the Yangtze River Delta Urban Agglomeration

2021 ◽  
Vol 18 (15) ◽  
pp. 8130
Author(s):  
Wenbo Cai ◽  
Wei Jiang ◽  
Hongyu Du ◽  
Ruishan Chen ◽  
Yongli Cai
Keyword(s):  
Ecosystem Services ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
River Delta ◽  
Urban Agglomeration ◽  
City Management ◽  
The Yangtze River ◽  
Social Demand ◽  
Urban Agglomerations ◽  
The Yangtze River Delta

With the global increase in population and urban expansion, the simultaneous rise of social demand and degradation of ecosystems is omnipresent, especially in the urban agglomerations of China. In order to manage environmental problems and match ecosystem supply and social demand, these urban agglomerations promoted regional socio-ecological integration but ignored differential city management during the process of integration. Therefore, it is necessary to design a general framework linking ecosystem supply and social demand to differential city management. In addition, in previous studies, ecosystem services supply–demand amount (mis)match assessment was emphasized, but ecosystem services supply–demand type (mis)match assessment was ignored, which may lead to biased decisions. To deal with these problems, this study presented a general ecosystem services framework with six core steps for differential city management and developed a double-indices (amount and type) method to identify ecosystem services supply–demand (mis)matches in an urban agglomeration. This framework and the double-indices method were applied in the case study of the Yangtze River Delta Urban Agglomeration. Ecosystem supply–demand amount and type (mis)match levels and spatial pattern of twenty-six cities were identified. Twenty-six cities in the YRDUA were classified into five kinds of cities with different levels of ES supply–demand (mis)matches for RS, three kinds of cities for PS, and four kinds of cities for CS. Differential city management strategies were designed. Despite its limitations, this study can be a reference to giving insights into ES supply–demand (mis)match assessment and management.

scholarly journals Ecological Environment Vulnerability and Driving Force of Yangtze River Urban Agglomeration

2019 ◽  
Vol 11 (23) ◽  
pp. 6623 ◽  
Author(s):  
Peng ◽  
Huang ◽  
Elahi ◽  
Wei
Keyword(s):  
Yangtze River ◽  
Spatial Clustering ◽  
Driving Factors ◽  
Urban Agglomeration ◽  
Ecological Environment ◽  
Driving Mechanism ◽  
The Yangtze River ◽  
Spatial Agglomeration ◽  
Urban Agglomerations ◽  
Study Results

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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