Population pattern and exposure under sea level rise: Low elevation coastal zone in the Yangtze River Delta, 1990-2100

AbstractA 52-m core from Qidong at the tip of the Yangtze River (Chang Jiang) delta provides a history of sea-level change, deltaic development, and vegetational and climatic changes during the last 12,000 yr. About 12,000 yr ago, when sea level was about 60 m below the present level, the coring site was situated in the innermost part of the exposed continental shelf. The late-Pleistocene vegetation on the uplands of the Lower Yangtze River valley was a mixed forest of deciduous and broadleaved evergreen trees in which Betula, Ulmus, Tsuga, and Cupressaceae were slightly more abundant than at present. Abies and Picea were probably present as relict populations on mountains bordering the region. Rapidly rising sea level converted the Qidong area to a coastal or estuarine environment between 11,000 and 10,800 yr B.P., leading to widespread development of wetlands dominated by Gramineae and Cyperaceae. During the next 2500 yr coastal erosion due to marine transgression obliterated the sedimentary record. Deltaic sedimentation predominated from 8300 to 3800 yr B.P., as the Yangtze River delta prograded by successively building a series of estuarine sand bars. During the mid-Holocene, the climate was slightly warmer and more humid than at present, allowing the subtropical broadleaved evergreen trees to increase their populations. Pinus and Quercus became more abundant after 3800 yr B.P. in response to climatic cooling. The present deltaic plain in Qidong formed less than 200 yr ago.

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Evaluating the energy efficiency of wastewater treatment plants in the Yangtze River Delta: Perspectives on regional discrepancies

Applied Energy ◽

10.1016/j.apenergy.2021.117087 ◽

2021 ◽

Vol 297 ◽

pp. 117087

Author(s):

Runyao Huang ◽

Ziheng Shen ◽

Hongtao Wang ◽

Jin Xu ◽

Zisheng Ai ◽

...

Keyword(s):

Energy Efficiency ◽

Wastewater Treatment ◽

Yangtze River ◽

Wastewater Treatment Plants ◽

Yangtze River Delta ◽

River Delta ◽

The Yangtze River ◽

The Yangtze River Delta

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Current Status and Temporal Trend of Potentially Toxic Elements Pollution in Agricultural Soil in the Yangtze River Delta Region: A Meta-Analysis

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18031033 ◽

2021 ◽

Vol 18 (3) ◽

pp. 1033

Author(s):

Shufeng She ◽

Bifeng Hu ◽

Xianglin Zhang ◽

Shuai Shao ◽

Yefeng Jiang ◽

...

Keyword(s):

Yangtze River ◽

Agricultural Soil ◽

Toxic Elements ◽

Temporal Trend ◽

Meta Analysis ◽

Yangtze River Delta ◽

Potentially Toxic Elements ◽

River Delta ◽

The Yangtze River ◽

The Yangtze River Delta

Potentially toxic elements (PTEs) pollution in the agricultural soil of China, especially in developed regions such as the Yangtze River Delta (YRD) in eastern China, has received increasing attention. However, there are few studies on the long-term assessment of soil pollution by PTEs over large regions. Therefore, in this study, a meta-analysis was conducted to evaluate the current state and temporal trend of PTEs pollution in the agricultural land of the Yangtze River Delta. Based on a review of 118 studies published between 1993 and 2020, the average concentrations of Cd, Hg, As, Pb, Cr, Cu, Zn, and Ni were found to be 0.25 mg kg−1, 0.14 mg kg−1, 8.14 mg kg−1, 32.32 mg kg−1, 68.84 mg kg−1, 32.58 mg kg−1, 92.35 mg kg−1, and 29.30 mg kg−1, respectively. Among these elements, only Cd and Hg showed significant accumulation compared with their background values. The eastern Yangtze River Delta showed a relatively high ecological risk due to intensive industrial activities. The contents of Cd, Pb, and Zn in soil showed an increasing trend from 1993 to 2000 and then showed a decreasing trend. The results obtained from this study will provide guidance for the prevention and control of soil pollution in the Yangtze River Delta.

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The Evolution of the Interactive Relationship between Urbanization and Land-Use Transition: A Case Study of the Yangtze River Delta

Land ◽

10.3390/land10080804 ◽

2021 ◽

Vol 10 (8) ◽

pp. 804

Author(s):

Bo Niu ◽

Dazhuan Ge ◽

Rui Yan ◽

Yingyi Ma ◽

Dongqi Sun ◽

...

Keyword(s):

Land Use ◽

Land Use Change ◽

Yangtze River ◽

Yangtze River Delta ◽

River Delta ◽

Socioeconomic Factor ◽

The Yangtze River ◽

Land Use Transition ◽

The Yangtze River Delta ◽

Interaction Relationship

In recent years, the impact of land-use systems on global climate change has become increasingly significant, and land-use change has become a hot issue of concern to academics, both within China and abroad. Urbanization, as an important socioeconomic factor, plays a vital role in promoting land-use transition, which also shows a significant spatial dependence on urbanization. This paper constructs a theoretical framework for the interaction relationship between urbanization and land-use transition, taking the Yangtze River Delta as an example, and measures the level of urbanization from the perspective of population urbanization, economic urbanization and social urbanization, while also evaluating the level of land-use morphologies from the perspective of dominant and recessive morphologies of land-use. We construct a PVAR model and coupled coordination model based on the calculated indexes for empirical analysis. The results show that the relationship between urbanization and land-use transition is not a simple linear relationship, but tends to be complex with the process of urbanization, and reasonable urbanization and land-use morphologies will promote further benign coupling in the system. By analyzing the interaction relationship between urbanization and land-use transition, this study enriches the study of land-use change and provides new pathways for thinking about how to promote high-quality urbanization.

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