Morphodynamic Simulation at the South Branch of Yangtze Estuary

Author(s):  
Xiaoyan Zhou ◽  
Ulrich Zanke ◽  
Yixin Yan ◽  
Jinhai Zheng

In this paper a numerical morphodynamic model TIMOR3 has been introduced and applied to simulate the morphological response to the water and sediment changes in the Yangtze River Estuary. TIMOR3, coupled with Hydrodynamic Model and Wave Model, is used to simulate a long-term and huge area of the morphological changes in the Yangtze River Estuary. A detailed investigation was made to the south branch where the Deepwater Channel Navigation Project is under construction. The effect of the project in different phases with different water depth has been simulated and analyzed.

2014 ◽  
Vol 1010-1012 ◽  
pp. 1099-1103
Author(s):  
Wei Na Zhang ◽  
Yi Gang Wang ◽  
Tong Jun Yang ◽  
Hui Ming Huang

Abstract. The saltwater intrusion in the Yangtze River Estuary is very frequent and complicated with a great effect on freshwater supply in Shanghai and nearby cities. By using the hydrologic data observed in dry season, the temporal and spatial variation of the saltwater intrusion in the Yangtze River Estuary were analyzed. The results show that the saltwater intrusion of the south branch is mainly induced by the saltwater spilling over from the north branch, which causes the Chenhang reservoir being plagued by saltwater intrusion during dry season. As the saltwater group from the north branch moving downward along the south branch, the longitudinal salinity distribution present a high-low-high shape during spring tide cycle, low-high-low-high shape during medium tide cycle and low-high shape during neap tide cycle along the south branch-south channel-south passage. Moreover, the north branch is controlled by high saline water with the increase of the salinity in the upstream reach in medium and spring tides, but this phenomenon is vanished in neap tide. In addition, the vertical distribution of salinity is more homogeneous in shoals than that in deep channels, which is induced by mixing degree in water column.


2017 ◽  
Vol 19 (6) ◽  
pp. 861-873 ◽  
Author(s):  
Guisheng Song ◽  
Yijie Li ◽  
Suzheng Hu ◽  
Guiju Li ◽  
Ruihua Zhao ◽  
...  

CDOM photobleaching in the Yangtze estuary is affected by its source, and water temperature and pH but not salinity.


2021 ◽  
Vol 13 (10) ◽  
pp. 1875
Author(s):  
Wenping Xie ◽  
Jingsong Yang ◽  
Rongjiang Yao ◽  
Xiangping Wang

Soil salt-water dynamics in the Yangtze River Estuary (YRE) is complex and soil salinity is an obstacle to regional agricultural production and the ecological environment in the YRE. Runoff into the sea is reduced during the impoundment period as the result of the water-storing process of the Three Gorges Reservoir (TGR) in the upper reaches of the Yangtze River, which causes serious seawater intrusion. Soil salinity is a problem due to shallow and saline groundwater under serious seawater intrusion in the YRE. In this research, we focused on the temporal variation and spatial distribution characteristics of soil salinity in the YRE using geostatistics combined with proximally sensed information obtained by an electromagnetic induction (EM) survey method in typical years under the impoundment of the TGR. The EM survey with proximal sensing method was applied to perform soil salinity survey in field in the Yangtze River Estuary, allowing quick determination and quantitative assessment of spatial and temporal variation of soil salinity from 2006 to 2017. We developed regional soil salinity survey and mapping by coupling limited laboratory data with proximal sensed data obtained from EM. We interpreted the soil electrical conductivity by constructing a linear model between the apparent electrical conductivity data measured by an EM 38 device and the soil electrical conductivity (EC) of soil samples measured in laboratory. Then, soil electrical conductivity was converted to soil salt content (soil salinity g kg−1) through established linear regression model based on the laboratory data of soil salinity and soil EC. Semivariograms of regional soil salinity in the survey years were fitted and ordinary kriging interpolation was applied in interpolation and mapping of regional soil salinity. The cross-validation results showed that the prediction results were acceptable. The soil salinity distribution under different survey years was presented and the area of salt affected soil was calculated using geostatistics method. The results of spatial distribution of soil salinity showed that soil salinity near the riverbanks and coastlines was higher than that of inland. The spatial distribution of groundwater depth and salinity revealed that shallow groundwater and high groundwater salinity influenced the spatial distribution characteristics of soil salinity. Under long-term impoundment of the Three Gorges Reservoir, the variation of soil salinity in different hydrological years was analyzed. Results showed that the area affected by soil salinity gradually increased in different hydrological year types under the impoundment of the TGR.


2008 ◽  
Vol 28 (3) ◽  
pp. 1174-1182 ◽  
Author(s):  
Zuo Tao ◽  
Wang Jun ◽  
Jin Xianshi ◽  
Li Zhongyi ◽  
Tang Qisheng

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