scholarly journals Monitoring and predicting the shoreline change in Can Gio area in condition of the sea level rise

2014 ◽  
Vol 17 (3) ◽  
pp. 45-53
Author(s):  
Vinh Trong Bui ◽  
Tin Trung Huynh ◽  
Trinh Nguyen Doan Le ◽  
Hoang Minh Ly ◽  
Phong Thanh Le ◽  
...  

Locating on the domestic and international navigation routes (Long Tau-Tac Dinh Cau route, Soai Rap route) the Can Gio area is impacted by waterway traffic activities. The seasonal movement of sand bars on the Can Gio is significantly impacted by hydrodynamic of the river mouth. With the important roles of the area, the authors consider the coastal morphology processes under the hydrodynamic. In this paper, the authors has inherited previous studies combined the satellite image analysis to detect the shoreline changes from 1973 to 2013. Besides, numerical modeling was also applied to predict the shoreline changes under impacts of the sea level rise. Results show that, the Can Gio shoreline prolonging from Can Thanh to Dong Hoa is seriously eroded, with average of 7-10 m/year, maximum to 15 m/year. It is found that, beach erosion at Can Gio is a kind of surface erosion impacted by human trigger (shrimp ponds, beach encroachment…). In addition, natural factors (wave, long-shore current, littoral materials) also contribute to increase the erosion rate. Predicted results with sea level rise scenarios show that, the Dong Hoa and Can Thanh will be seriously eroded while the 30-4 beach will be annually deposited.

2012 ◽  
Vol 1 (33) ◽  
pp. 35
Author(s):  
Jun Yoshida ◽  
Keiko Udo ◽  
Yuriko Takeda ◽  
Akira Mano

Coastal erosion caused by sea level rise is a serious problem for people all over the world. Global sea level will rise from 0.18 to 0.59 m (IPCC, 2007). Along the coasts in Japan, sea level will rise from 0.09 to 0.27 m by the end of this century. The future estimation considers only thermal expansion due to rising sea temperature caused by global warming. However, considering the contribution of scale-down of Greenland and Antarctic ice sheet, there is potential of the increase in the rate of sea level rise. There are few studies which evaluate impacts of the future beach erosion on society by comparing with the past shoreline change resulting from natural forces and human activities. This study evaluates the long-term shoreline changes due to natural forces and human activities by using old maps. Shoreline changes were influenced by natural forces from 1900 to 1950 and were influenced by human activities from 1950 to 1990. Shoreline changes showed that the changes tended to be stable after 1990, and coastal erosion due to climate change would likely become obvious in the future.


2019 ◽  
Vol 270 ◽  
pp. 04023
Author(s):  
Asrini Chrysanti ◽  
Mohammad Bagus Adityawan ◽  
Widyaningtyas ◽  
Bagus Pramono Yakti ◽  
Joko Nugroho ◽  
...  

Kulon Progo Airport is an airport development project located in the coastal area near Yogyakarta, Indonesia, which is expected to complete in 2019. With the increase in population, huge land acquisition will be difficult, so the development of coastal areas for the airport became inevitable. Kulon Progo is located in the disaster-prone zone area of the earthquake and tsunami, the airport design must consider the risk management and mitigation from tsunami and earthquake disaster. Although the airport is already calculated the danger of earthquake and tsunami, the development of the coastal area also needs to consider the danger of the natural coastal process itself such as sedimentation and erosion. Shoreline changes due to the new infrastructure in the coastal area can disrupt the equilibrium of coastal process especially the longshore sediment transport. A satellite image shows that Kulon Progo shoreline retreats over 60 meters due to the heavy sediment longshore transport in the past 10 years. Breakwaters in Tanjung Adikarto fishing port also made a great contribution in huge sedimentation behind the infrastructure up to 90 meters. This research will conduct an analysis trough satellite and numerical model to observe the shoreline changes along Kulon Progo Coast. A numerical model shows a high erosion rate along the coast. High sedimentation also observed at the river mouth of Bogowonto and Serang Rivers.


Shore & Beach ◽  
2020 ◽  
pp. 3-13
Author(s):  
James Houston

Beach nourishment and sea level rise will dominate future shoreline changes on Florida’s 665 miles of sandy coast. Shoreline changes from 2020-2100 are projected along this entire coast using equilibrium profile theory that accurately predicted shoreline changes on Florida’s east coast from 1970-2017 (Houston 2019). Projections for 2020- 2100 are made assuming past rates of beach nourishment for the 30-yr period from 1988-2017 will continue and sea level will rise according to recent projections of the Intergovernmental Panel on Climate Change (IPCC) that include the latest knowledge on ice melting in Antarctica (IPCC 2019). Using the beach nourishment and sea level rise data, equilibrium profile theory is then used to predict shoreline change from 2020-2100 for each IPCC sea level rise projection. Beach nourishment is shown to produce shoreline advance seaward on average for all IPCC scenarios for both the entire Florida coast and east coast and for all scenarios except the upper confidence level of the worst scenario for the southwest and Panhandle coasts. Some of the 30 counties on these coasts will require a greater rate of nourishment than in the past to offset sea level rise for some or all of the scenarios, whereas some will offset sea level rise for all scenarios with lower nourishment rates than in the past. The annual beach nourishment volume for which a county has a shortfall or surplus in offsetting sea level rise for each IPCC scenario can be calculated with the information provided and examples are presented. The approach can be used on coasts outside Florida if beach nourishment and sea level rise are expected to dominate future shoreline change.


Author(s):  
Yoshiaki Kuriyama ◽  
Masayuki Banno

Submerged breakwaters are considered to be preferable countermeasures against beach erosion where the availability of sediments for nourishment is limited and tourism is prevalent because submerged breakwaters do not interfere with the view of the horizon from the shore. However, sandy beaches protected by submerged breakwaters are assumed to be vulnerable to relative sea level rise (SLR) and land subsidence because the crests of submerged breakwaters are below sea level. Kuriyama and Banno (2016) numerically predicted the future shoreline change under SLR and land subsidence on the Niigata West coast in Japan, which is protected by submerged breakwaters. The prediction showed that the shoreline will retreat 60 m over the next 100 years. In this study, we investigated the effects of countermeasures against the erosion due to SLR and land subsidence.


2021 ◽  
Vol 9 (9) ◽  
pp. 974
Author(s):  
Maurizio D’Anna ◽  
Deborah Idier ◽  
Bruno Castelle ◽  
Sean Vitousek ◽  
Goneri Le Cozannet

Long-term (>decades) coastal recession due to sea-level rise (SLR) has been estimated using the Bruun Rule for nearly six decades. Equilibrium-based shoreline models have been shown to skillfully predict short-term wave-driven shoreline change on time scales of hours to decades. Both the Bruun Rule and equilibrium shoreline models rely on the equilibrium beach theory, which states that the beach profile shape equilibrates with its local wave and sea-level conditions. Integrating these two models into a unified framework can improve our understanding and predictive skill of future shoreline behavior. However, given that both models account for wave action, but over different time scales, a critical re-examination of the SLR-driven recession process is needed. We present a novel physical interpretation of the beach response to sea-level rise, identifying two main contributing processes: passive flooding and increased wave-driven erosion efficiency. Using this new concept, we analyze the integration of SLR-driven recession into equilibrium shoreline models and, with an idealized test case, show that the physical mechanisms underpinning the Bruun Rule are explicitly described within our integrated model. Finally, we discuss the possible advantages of integrating SLR-driven recession models within equilibrium-based models with dynamic feedbacks and the broader implications for coupling with hybrid shoreline models.


Author(s):  
Le Xuan Thuyen

A small mangrove colony growing for several decades on a mud flat on the left side of Balat River mouth has become today a large and healthy forest, containing a high ecosystem service value in the core of the Red River biosphere reserve. As a pioneer ecosystem located at land– water interface in the tropic, there exist always risks to mangroves, especially due to climate change and sea level rise. Sea level rise is a worldwide process, but subsidence is a local problem that can exacerbate these geo-hazards. A monitoring of shallow subsidence has been carried out by using SET-MH technique (developed by the United States Geological Survey) to track the both accretion and land sinking in the core zone of the National Park. The measurement shows the average sedimentation rate of 2.9 cm / yr and the sinking rate of 3.4 cm / yr, since Dec. 30th 2012. This is the first ground-based observation of shallow subsidence under mangroves in the Tonkin Gulf. As a simple and low cost method, so further expansion of this monitoring could provide more useful information to help identify the generally sinking trend of coastal areas in the Red River Delta and also to protect its own biosphere reserve.


2020 ◽  
Author(s):  
Andy Emery ◽  
David Hodgson ◽  
Natasha Barlow ◽  
Carol Cotterill

<p>Coastal landforms such as barriers are crucial in protecting coastlines and reducing the rate of erosion and retreat. Sea-level rise threatens to change the baseline in which such landforms exist, therefore changing sediment fluxes and hydrodynamics at coastlines. Understanding the stability of landforms under changing conditions is crucial to protect and mitigate against the influence of future sea-level rise on coastal infrastructure, ecology and populations. By studying past periods of sea-level rise with rates similar to those projected for the future, we can begin to understand how coastlines may evolve over the next few centuries.</p><p>Dogger Bank, in the southern North Sea, experienced marine transgression during the Early Holocene. Over a period of 800 years, sea level rose by 7-8 m. This rate of ~10 mm/yr is similar to that projected within the next century. Our study area is located on the southeastern side of the former Dogger Bank island. Between 9.5 and 8.7 ka BP, two phases of coastal barriers were present, retreating with different mechanisms at different time periods due to antecedent topographic changes and evolving hydrodynamics. Barrier phase A was drowned in place due to a low-angle topography and little reworking of the barrier. Barrier phase B retreated by continuous overstepping, which occurred due to a higher-angle topography and an increase in wave energy. Complete inundation of the study area occurred by 8.7 ka, with the barrier phase B first becoming an isolated barrier, then breaking down completely. The subsequent wave ravinement transitioned the landform from barrier to offshore sand bar. At this time, the rate of sea-level rise had increased to as much as 20 mm/yr during the pre-8.2 ka sea-level jump, causing the final barrier breakdown and inundation of Dogger Bank. The coastal morphology in the study area is now buried beneath up to 20 m of shallow marine sand, deposited as the dominant tidal current transported sediment from west to east.</p><p>The unique landform preservation at Dogger Bank allows unprecedented spatial and temporal resolution into the investigation of coastal response to sea-level rise. This study adds evidence to the growing body of work that sea-level rise is the driver of, but not necessarily the controlling factor in, barrier retreat mechanism. Furthermore, a rarely-preserved landform, the isolated barrier, is presented. The results of the study provide valuable insights into the transition from coastal to fully marine during transgression of low-relief coastal areas, which provides an analogue for future sea-level rise scenarios.</p>


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