scholarly journals Thresholds for morphological changes on an exposed sandy beach as a function of wave height

2010 ◽  
Vol 36 (4) ◽  
pp. 523-532 ◽  
Author(s):  
L. P. Almeida ◽  
Ó. Ferreira ◽  
A. Pacheco
Keyword(s):  
Wave Height ◽  
Sandy Beach ◽  
Morphological Changes

Investigation of coastal morphological changes due to river basin characteristics by means of remote sensing and GIS techniques

2003 ◽  
Vol 48 (10) ◽  
pp. 135-142 ◽  
Author(s):  
D.Z. Seker ◽  
C. Goksel ◽  
S. Kabdasli ◽  
N. Musaoglu ◽  
S. Kaya
Keyword(s):  
Black Sea ◽  
Satellite Data ◽  
Satellite Images ◽  
Sandy Beach ◽  
Morphological Changes ◽  
Remote Sensing And Gis ◽  
The Black Sea ◽  
Black Sea Coast ◽  
Delta Formation ◽  
Bathymetric Changes

The Riva River is located on the Anatolian (Asian) side of Istanbul by the Black Sea coast, with a wonderful sandy beach and delta formation which has been selected as the study area. The Riva is the largest river in this region, which flows into the Black Sea and also gives its’ name to the area. The river carries some amount of sediments to the Black Sea. These particles cause considerable changes not only in the bed bathymetry and coastal boundaries of the river but also along the coastline of the Black Sea. The aim of this study is to determine these variations by means of satellite data and GIS. In the study, satellite images dated 1975, 1984, 1992 and 2001 have been used. At the end of the study, the possibility of observing bathymetric changes in front of the coastline by means of satellite data has been investigated and results were evaluated and visualised by means of GIS.

Morphological changes in a cuspate sandy beach under persistent high-energy swells: Reñaca Beach (Chile)

2019 ◽  
Vol 417 ◽  
pp. 105988
Author(s):  
R. Agredano ◽  
R. Cienfuegos ◽  
P Catalán ◽  
E. Mignot ◽  
P. Bonneton ◽  
...  
Keyword(s):  
Sandy Beach ◽  
Morphological Changes ◽  
High Energy

scholarly journals Investigation of Morphological Changes in the Tamsui River Estuary Using an Integrated Coastal and Estuarine Processes Model

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1084 ◽  
Author(s):  
Tung-Chou Hsieh ◽  
Yan Ding ◽  
Keh-Chia Yeh ◽  
Ren-Kai Jhong
Keyword(s):  
Sandy Beach ◽  
Morphological Changes ◽  
River Estuary ◽  
River Mouth ◽  
Physical Processes ◽  
Complex Flow ◽  
Monsoon Period ◽  
Estuarine Processes ◽  
Sediment Flushing ◽  
The Impact

This study is to investigate morphological changes in the Tamsui River Estuary in Taiwan driven by multiple physical processes, such as river flows, tides, waves, and storm surges, and then to study the impacts of sediment flushing operated at the Shihmen reservoir upstream on the river estuary. An integrated coastal and estuarine processes model (CCHE2D-Coast) (Center for Computational Hydroscience and Engineering Two-Dimensional-Coast) was validated by simulating these physical processes in the estuary driven by three historical typhoons in 2008. The site-specifically validated model was then applied to simulate morphological changes in the estuary in response to reservoir sediment flush scenarios from the upstream. For the impact assessment of sediment flushing, a synthetic hydrological event was designed by including a historical typhoon and a typical monsoon. It was found that during the typhoon, the sediments will be mostly deposited in the estuarine river reach of Tamsui and the Wazihwei sandy beach. During the monsoon period, most of the sediments tend to be deposited in the second fishing port of Tamsui, the northern breakwater, and the estuary, while the Wazihwei sandy beach in the river mouth would be scoured by backflow. Simulations of the complex flow fields and morphological changes will facilitate the best practice of sediment management in the coastal and estuarine regions.

scholarly journals APPLYING UAV AND PHOTOGRAMMETRY TO MONITOR THE MORPHOLOGICAL CHANGES ALONG THE BEACH IN PENGHU ISLANDS

2016 ◽  
Vol XLI-B8 ◽  
pp. 1153-1156
Author(s):  
Cheng-Hao Lu
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Sandy Beach ◽  
Temporal Change ◽  
Morphological Changes ◽  
Rip Current ◽  
Shield Volcano ◽  
Coastal Structures ◽  
Aerial Vehicles ◽  
Southern Taiwan ◽  
Penghu Islands

Penghu islands, in the southern Taiwan Strait, is a remnant of a middle-late Miocene basaltic shield volcano. We present a procedure to use UAV (Unmanned Aerial Vehicles) to perform photogrammetry survey and monitoring analysis in beach evolution scenarios. The aim of this study is to understand spatial-temporal change along the sandy beach in Penghu islands, especially as for the effects of typhoon and coastal structures. According to the study result, this example of application is provided to show the results and the potential of this methodology in real beach changes. In addition, we found the typhoon and coastal structures play important roles to shape the beach morphology and its evolution. The result of beach monitoring reveals that the reduction and change of sand volume in Shanshui beach resulted from the placement of detached breakwater complexes. This coastal structure likely resulted in the development of tombolo and therefor make the beach unstable and subject to conduct rip current and more erosion.

scholarly journals Field and Numerical Study of Resistance and Resilience on a Sea Breeze Dominated Beach in Yucatan (Mexico)

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1806 ◽  
Author(s):  
Gabriela Medellín ◽  
Alec Torres-Freyermuth ◽  
Giuseppe Tomasicchio ◽  
Antonio Francone ◽  
Peter Tereszkiewicz ◽  
...  
Keyword(s):  
Sandy Beach ◽  
Temporal Evolution ◽  
Numerical Study ◽  
Morphological Changes ◽  
Sea Breeze ◽  
Eof Analysis ◽  
Field Surveys ◽  
Orthogonal Function ◽  
Alongshore Sediment Transport ◽  
Transport Potential

The understanding of the beach capability to resist and recover from a disturbance is of paramount importance in coastal engineering. However, few efforts have been devoted to quantifying beach resilience. The present work aims to investigate the shoreline resistance and resilience, associated to a transient disturbance, on a sandy beach. A temporary groin was deployed for 24 h on a micro-tidal sea-breeze dominated beach to induce a shoreline perturbation. Morphological changes were measured by means of beach surveys to estimate the beach perturbation and the further beach recovery after structure removal. An Empirical Orthogonal Function (EOF) analysis of the shoreline position suggests that the first EOF mode describes the spatial-temporal evolution of the shoreline owing to the groin deployment/removal. A new one-line numerical model of beach evolution is calibrated with the field surveys, reproducing both the sediment impoundment and subsequent beach recovery after the structure removal. Thus, a parametric numerical study is conducted to quantify resistance and resilience. Numerical results suggest that beach resistance associated to the presence of a structure decreases with increasing alongshore sediment transport potential, whereas resilience after structure removal is positively correlated with the alongshore diffusivity.

scholarly journals Field Investigation of Morphological Changes in Lagoonal Sandy Beach of Atoll Islands

2011 ◽  
Vol 67 (2) ◽  
pp. I_1331-I_1335
Author(s):  
Daisaku SATO ◽  
Hiromune YOKOKI ◽  
Ane TALIA
Keyword(s):  
Sandy Beach ◽  
Morphological Changes ◽  
Field Investigation

scholarly journals Lidar Observations of the Swash Zone of a Low-Tide Terraced Tropical Beach under Variable Wave Conditions: The Nha Trang (Vietnam) COASTVAR Experiment

2020 ◽  
Vol 8 (5) ◽  
pp. 302 ◽  
Author(s):  
Luís Pedro Almeida ◽  
Rafael Almar ◽  
Chris Blenkinsopp ◽  
Nadia Senechal ◽  
Erwin Bergsma ◽  
...  
Keyword(s):  
Field Experiment ◽  
Wave Height ◽  
Sandy Beach ◽  
Wind Waves ◽  
Swash Zone ◽  
Key Factor ◽  
Wave Conditions ◽  
Run Up ◽  
Topographic Surveys ◽  
Lidar Observations

A field experiment was conducted at a tropical microtidal intermediate sandy beach with a low tide terrace (Nha Trang, Vietnam) to investigate the short-term swash-zone hydrodynamics and morphodynamics under variable wave conditions. Continuous 2D Lidar scanner observations of wave height at the lower foreshore, subsequent run-up and swash-induced topographic changes were obtained. These data were complemented by detailed real-time kinematic GPS topographic surveys. Variable wave and tide conditions were experienced during the field experiment with relatively large swell waves (offshore significant wave height, Hs = 0.9 m to 1.3 m; peak wave period, Tp = 8 to 12 s) concomitant with spring tides at the beginning of the period, followed by mild wind waves (offshore Hs under 0.5 m and Tp 5 s) and neap tides. This resulted in the following morphological sequence: berm erosion followed by rapid neap berm reformation and beach recovery within a few days. New insights into the link between intra-tidal swash dynamics and daily beach profile evolution were found using the Lidar dataset. While waves directly cause morphology changes on a wave-by-wave basis, tidal levels were found to be a key factor in determining the morphological wave-effect (accretive or erosive) due to modulated interaction between surf and swash hydro-morphodynamics.

scholarly journals APPLYING UAV AND PHOTOGRAMMETRY TO MONITOR THE MORPHOLOGICAL CHANGES ALONG THE BEACH IN PENGHU ISLANDS

2016 ◽  
Vol XLI-B8 ◽  
pp. 1153-1156 ◽  
Author(s):  
Cheng-Hao Lu
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Sandy Beach ◽  
Temporal Change ◽  
Morphological Changes ◽  
Rip Current ◽  
Shield Volcano ◽  
Coastal Structures ◽  
Aerial Vehicles ◽  
Southern Taiwan ◽  
Penghu Islands

Penghu islands, in the southern Taiwan Strait, is a remnant of a middle-late Miocene basaltic shield volcano. We present a procedure to use UAV (Unmanned Aerial Vehicles) to perform photogrammetry survey and monitoring analysis in beach evolution scenarios. The aim of this study is to understand spatial-temporal change along the sandy beach in Penghu islands, especially as for the effects of typhoon and coastal structures. According to the study result, this example of application is provided to show the results and the potential of this methodology in real beach changes. In addition, we found the typhoon and coastal structures play important roles to shape the beach morphology and its evolution. The result of beach monitoring reveals that the reduction and change of sand volume in Shanshui beach resulted from the placement of detached breakwater complexes. This coastal structure likely resulted in the development of tombolo and therefor make the beach unstable and subject to conduct rip current and more erosion.

Morphological Changes in the Rat Granulosa Cell Surface During Differentiation Induced by Estradiol and Gonadotropins

1977 ◽  
Vol 35 ◽  
pp. 484-485
Author(s):  
P. Bagavandoss ◽  
JoAnne S. Richards ◽  
A. Rees Midgley
Keyword(s):  
Cell Surface ◽  
Granulosa Cell ◽  
Morphological Changes ◽  
Follicular Development ◽  
Female Rats ◽  
Functional Changes ◽  
Group 4 ◽  
Group 3 ◽  
Group 5 ◽  
Group 2

During follicular development in the mammalian ovary, several functional changes occur in the granulosa cells in response to steroid hormones and gonadotropins (1,2). In particular, marked changes in the content of membrane-associated receptors for the gonadotropins have been observed (1).We report here scanning electron microscope observations of morphological changes that occur on the granulosa cell surface in response to the administration of estradiol, human follicle stimulating hormone (hFSH), and human chorionic gonadotropin (hCG).Immature female rats that were hypophysectcmized on day 24 of age were treated in the following manner. Group 1: control groups were injected once a day with 0.1 ml phosphate buffered saline (PBS) for 3 days; group 2: estradiol (1.5 mg/0.2 ml propylene glycol) once a day for 3 days; group 3: estradiol for 3 days followed by 2 days of hFSH (1 μg/0.1 ml) twice daily, group 4: same as in group 3; group 5: same as in group 3 with a final injection of hCG (5 IU/0.1 ml) on the fifth day.

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