scholarly journals Tidal asymmetry and velocity skew over tidal flats and shallow channels within a macrotidal river delta

2012 ◽  
Vol 117 (C3) ◽  
pp. n/a-n/a ◽  
Author(s):  
N. J. Nidzieko ◽  
D. K. Ralston
Keyword(s):  
Tidal Flats ◽  
River Delta ◽  
Tidal Asymmetry

scholarly journals Rapid Loss of Tidal Flats in the Yangtze River Delta since 1974

2020 ◽  
Vol 17 (5) ◽  
pp. 1636 ◽  
Author(s):  
Xing Li ◽  
Xin Zhang ◽  
Chuanyin Qiu ◽  
Yuanqiang Duan ◽  
Shu’an Liu ◽  
...  
Keyword(s):  
Yangtze River ◽  
Yangtze River Delta ◽  
Yangtze Estuary ◽  
Tidal Flats ◽  
River Delta ◽  
Sediment Supply ◽  
The Yangtze River ◽  
Landsat Images ◽  
National Nature Reserves ◽  
The Yangtze River Delta

As the home to national nature reserves and a Ramsar wetland, the tidal flats of the Yangtze River Delta are of great significance for ecological security, at both the local and global scales. However, a comprehensive understanding of the spatiotemporal conditions of the tidal flats in the Yangtze River Delta remains lacking. Here, we propose using remote sensing to obtain a detailed spatiotemporal profile of the tidal flats, using all available Landsat images from 1974 to 2018 with the help of the Google Earth Engine cloud platform. In addition, reclamation data were manually extracted from time series Landsat images for the same period. We found that approximately 40.0% (34.9–43.1%) of the tidal flats in the study area have been lost since 1980, the year in which the tidal flat area was maximal. The change in the tidal flat areas was consistent with the change in the riverine sediment supply. We also found that the cumulative reclamation areas totaled 816.6 km2 and 431.9 km2 in the Yangtze estuary zone and along the Jiangsu coast, respectively, between 1974 and 2018. Because of reclamation, some areas (e.g., the Hengsha eastern shoal and Pudong bank), which used to be quite rich, have lost most of their tidal flats. Currently, almost 70% of the remaining tidal flats are located in the shrinking branch (North Branch) and the two National Nature Reserves (Chongming Dongtan and Jiuduansha) in the Yangtze estuary zone. Consequently, the large-scale loss of tidal flats observed was primarily associated with reduced sediment supply and land reclamation at the time scale of the study. Because increasing demand for land and rising sea levels are expected in the future, immediate steps should be taken to prevent the further deterioration of this valuable ecosystem.

Incremental transformation of a traditional village in China's Pearl River Delta

TERRITORIO ◽  
2015 ◽  
pp. 121-129 ◽  
Author(s):  
Peter Bosselmann ◽  
Francesca Frassoldati ◽  
Ping Su ◽  
Haohao Xu
Keyword(s):  
Pearl River Delta ◽  
River Delta ◽  
Pearl River
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