scholarly journals A novel approach for the assessment of morphological evolution based on observed water levels in tide-dominated estuaries

2020 ◽  
Author(s):  
Cai Huayang ◽  
Feng Liu
Keyword(s):  
Land Reclamation ◽  
Morphological Changes ◽  
Morphological Evolution ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Water Levels ◽  
Tidal Range ◽  
Good Correspondence ◽  
Wave Celerity ◽  
Tidal Hydrodynamics

<p>Assessing the impacts of both natural (e.g., tidal forcing from the ocean) and human-induced changes (e.g., dredging for navigation, land reclamation) on estuarine morphology is particularly important for the protection and management of the estuarine environment. In this study, a novel analytical approach is proposed for the assessment of estuarine morphological evolution in terms of tidally averaged depth on the basis of the observed water levels along the estuary. The key lies in deriving a relationship between wave celerity and tidal damping or amplification. For given observed water levels at two gauging stations, it is possible to have a first estimation of both wave celerity (distance divided by tidal travelling time) and tidal damping or amplification rate (tidal range difference divided by distance), which can then be used to predict the morphological changes via an inverse analytical model for tidal hydrodynamics. The proposed method is applied to the Lingdingyang Bay of the Pearl River Estuary, located on the southern coast of China, to analyse the historical development of the tidal hydrodynamics and morphological evolution. The analytical results show surprisingly good correspondence with observed water depth and volume in this system. The merit of the proposed method is that it provides a simple approach for understanding the decadal evolution of the estuarine morphology through the use of observed water levels, which are usually available and can be easily measured.</p>

scholarly journals A novel approach for the assessment of morphological evolution based on observed water levels in tide-dominated estuaries

2020 ◽  
Vol 24 (4) ◽  
pp. 1871-1889
Author(s):  
Huayang Cai ◽  
Ping Zhang ◽  
Erwan Garel ◽  
Pascal Matte ◽  
Shuai Hu ◽  
...  
Keyword(s):  
Land Reclamation ◽  
Morphological Changes ◽  
Morphological Evolution ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Water Levels ◽  
Tidal Range ◽  
Good Correspondence ◽  
Wave Celerity ◽  
Tidal Hydrodynamics

Abstract. Assessing the impacts of both natural (e.g. tidal forcing from the ocean) and human-induced changes (e.g. dredging for navigation and land reclamation) on estuarine morphology is particularly important for the protection and management of the estuarine environment. In this study, a novel analytical approach is proposed for the assessment of estuarine morphological evolution in terms of tidally averaged depth on the basis of the observed water levels along the estuary. The key lies in deriving a relationship between wave celerity and tidal damping or amplification. For given observed water levels at two gauging stations, it is possible to have a first estimation of both wave celerity (distance divided by tidal travelling time) and tidal damping or amplification rate (tidal range difference divided by distance), which can then be used to predict the morphological changes via an inverse analytical model for tidal hydrodynamics. The proposed method is applied to the Lingdingyang Bay of the Pearl River Estuary, located on the southern coast of China, to analyse the historical development of the tidal hydrodynamics and morphological evolution. The analytical results show surprisingly good correspondence with observed water depth and volume in this system. The merit of the proposed method is that it provides a simple approach for understanding the decadal evolution of the estuarine morphology through the use of observed water levels, which are usually available and can be easily measured.

scholarly journals A novel approach for the assessment of morphological evolution based on observed water levels in tide-dominated estuaries

2020 ◽  
Author(s):  
Huayang Cai ◽  
Ping Zhang ◽  
Erwan Garel ◽  
Pascal Matte ◽  
Shuai Hu ◽  
...  
Keyword(s):  
Land Reclamation ◽  
Morphological Changes ◽  
Morphological Evolution ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Water Levels ◽  
Tidal Range ◽  
Good Correspondence ◽  
Wave Celerity ◽  
Tidal Hydrodynamics

Abstract. Assessing the impacts of both natural (e.g., tidal forcing from the ocean) and human-induced changes (e.g., dredging for navigation, land reclamation) on estuarine morphology is particularly important for the protection and management of the estuarine environment. In this study, a novel analytical approach is proposed for the assessment of estuarine morphological evolution in terms of tidally averaged depth on the basis of the observed water levels along the estuary. The key lies in deriving a relationship between wave celerity and tidal damping or amplification. For given observed water levels at two gauging stations, it is possible to have a first estimation of both wave celerity (distance divided by tidal travelling time) and tidal damping or amplification rate (tidal range difference divided by distance), which can then be used to predict the morphological changes via an inverse analytical model for tidal hydrodynamics. The proposed method is applied to the Lingdingyang Bay of the Pearl River Estuary, located on the southern coast of China, to analyse the historical development of the tidal hydrodynamics and morphological evolution. The analytical results show surprisingly good correspondence with observed water depth and volume in this system. The merit of the proposed method is that it provides a simple approach for understanding the decadal evolution of the estuarine morphology through the use of observed water levels, which are usually available and can be easily measured.

scholarly journals Seasonal Tidal Dynamics in the Qiantang Estuary: The Importance of Morphological Evolution

2021 ◽  
Vol 9 ◽  
Author(s):  
Dongfeng Xie ◽  
Zheng Bing Wang
Keyword(s):  
River Discharge ◽  
Morphological Changes ◽  
Morphological Evolution ◽  
Sediment Accumulation ◽  
Water Levels ◽  
Tidal Range ◽  
Tidal Dynamics ◽  
Bathymetric Data ◽  
Bed Erosion

Despite the increasing number of studies on the river-tide interactions in estuaries, less attention has been paid to the role of seasonal morphological changes on tidal regime. This study analyzes the seasonal interplay of river and tide in the Qiantang Estuary, China, particularly focusing on the influences of the active morphological evolution induced by the seasonal variation of river discharge. The study is based on the high and low water levels at three representative stations along the estuary and daily river discharge through 2015, an intermediate flow year in which a typical river flood occurred, as well as the bathymetric data measured in April, July and November, 2015. The results show strong seasonal variations of the water level in addition to the spring-neap variation. These variations are obviously due to the interaction between river discharge and tide but can only be fully explained by including the effect of morphological changes. Two types of the influences of the variation of the river discharge on the tidal dynamics in the estuary can be distinguished: one is immediately induced by the high flow and the other continues for a much longer period because of the bed erosion and the following bed recovery. Tidal range in the upper reach can be doubled after the flood because of bed erosion and then decrease under normal discharge periods due to sediment accumulation. Over a relatively short term such as a month or a spring-neap tidal cycle, there exist good relationships between the tidal range, tidal amplification in the upper reach and the tidal range at the mouth, and between the hydraulic head over the upper and lower reaches. Such relationships are unclear if all data over the whole year are considered together, mainly because of the active morphological evolution.

Hydrodynamic Impact on Pearl River Estuary from HZM Bridge

2014 ◽  
Vol 488-489 ◽  
pp. 475-478 ◽  
Author(s):  
Jie He ◽  
Wen Jie Xin
Keyword(s):  
River Estuary ◽  
Pearl River Estuary ◽  
Tidal Range ◽  
Pearl River ◽  
Bridge Site ◽  
Hydrodynamic Impact ◽  
The Pearl River Estuary ◽  
The Pearl River ◽  
Hydrodynamic Environment ◽  
Hydrodynamic Influence

The HZM(Hongkong-Zhuhai-Macao) bridge connects Hongkong, Zhuhai and Macao district, and it strctchs across the Pearl River estuary. A lot of piers and three large artifical islands would have some impact on the hydrodynamic environment in the Pear River estuary. In this paper, a 2D tidal current numerical model is introduced to simulate the hydrodynamic impact from the HZM brdige. The simulated results show that the Hydrodynamic influence is concentrated on the 5.0 km range from downstream to upstream nearby the navigation zone and the 1.0 km range of bridge site in not-navigation zone, and the tidal range reduction is limited 0.03m and the tidal prism reduction is not more than 1% in the Lingding Sea after the HZM bridge constructed. Therefore, the HZM bridge has little influence on the distribution of hydrodynamic environment in the Pearl River estuary.

Morphodynamic Process of Dachan Bay in Pearl River Estuary Affected by Human Activities

2014 ◽  
Vol 638-640 ◽  
pp. 1257-1260
Author(s):  
Rong Yao Ji ◽  
Qun Xu ◽  
Si Ping Mo
Keyword(s):  
Tidal Flat ◽  
Human Activities ◽  
Large Scale ◽  
Morphological Changes ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Pearl River ◽  
Landsat Images ◽  
Change Analysis ◽  
Factors Affecting

The surrounding area of the Dachan Bay in the Pearl River Estuary has one of the highest economic development rates of China. Rapid industrialization and urbanization has resulted in extensive changes in land use, including the tidal flat reclamation and harbor construction. For the analysis of the morphological changes of the Dachan Bay, multi-temporal Landsat images have been digitized by using the integrated RS and GIS technique, and the digital elevation modes in different years were set up in combination with topographical and nautical data. From the change analysis, it can be concluded that the sea area of the Dachan Bay decreases to 6.0 km2, by 87.6% between 1907a and 2011a due to the large-scale tidal flat reclamation, and the maximum downcutting depth of the seabed in the entrance area is over 10m mainly caused by extensive harbor construction. Based on the research of the morphological change in recent decades, it is suggested that the human activities have become one of the major factors affecting the morphological processes of the Dachan Bay.

scholarly journals Spectral Analysis on Sub-Tidal Variability of Salinity in Modaomen Waterway of Pearl River Estuary, China

2012 ◽  
Vol 518-523 ◽  
pp. 1982-1985
Author(s):  
Yuan Ying Chen ◽  
Xiao Ling Yin ◽  
Dong Lin Bai ◽  
Li Cheng Li
Keyword(s):  
Time Series ◽  
Spectral Analysis ◽  
Response Time ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Tidal Range ◽  
Pearl River ◽  
Estuary Mouth ◽  
Power Spectrum Method ◽  
Tidal Variability

Salinity and tidal range time series observed in Modaomen waterway was analyzed in power spectrum method, and both showed the period of half month (14.22d). Moreover, the salinity and tidal range time series were coherent at that period through cross spectrum analysis. Besides, the phase analysis at the period of 14.22d showed that, within the estuary, the salinity time series upstream lagged that of the downstream, and the response time of salinity time series to the tidal range time series was about 9-10d, increasing upstream. But the phase of salinity time series and response time to the tidal range at the estuary mouth did not correspond with the laws within the estuary. The response time of salinity to the tidal range was about 12d there.

Study on the Characteristics of Temporal and Spatial Variation of Suspended Sediment in the Pearl River Estuary

2009 ◽  
Author(s):  
Wei Zhang ◽  
Mingyuan Yang ◽  
Xiaolin Zhang ◽  
Peipei Dong
Keyword(s):  
Spatial Variation ◽  
Suspended Sediment ◽  
Large Scale ◽  
Research Result ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Tidal Range ◽  
Pearl River ◽  
Temporal And Spatial Variation ◽  
Temporal And Spatial

The Lingding Estuary is one of the main parts of the whole Pearl River Delta, which lies in the South Sea, China. It is about 60 km wide from Hong Kong in the east to Macao in the west and the water areas are approximately 2110 km2. The process of suspended sediment movement is influenced by many factors, such as the estuarine geometry, tidal range and ravine flows etc.. In this paper, large scale hydrological observations in the Lingding Estuary have been respectively carried out in July, 2003. Based on these data, characteristics of temporal and spatial variation of suspended sediment concentration (SSC) in the Lingding Estuary are studied. The research result shows that SSC changes with the variation of tide current and runoff, the sediment re-suspension is often occurred 1–2 hour following the flood or ebb tide. The maximum turbidity appears near the gauging station V3. In the flood dominant stage, the sediments move towards the mainland, while during the ebb sediments move down.

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