Coastal Flooding Initiated by Wave Overtopping at Sea Defences

Author(s):  
Marcel R. A. van Gent
Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 237
Author(s):  
José Carlos Ferreira ◽  
Fábio Santos Cardona ◽  
Catarina Jóia Santos ◽  
José António Tenedório

Coastal areas are densely populated areas, and they have been experiencing increasing pressures as a consequence of population growth, but also because of climate change aggravation. For this reason, hazard, vulnerability, and risk indexes have been becoming more recurrent, especially to study and analyze low-lying coastal areas. This study presents an analysis on wave overtopping and coastal flooding, using an Analytic Hierarchy Process (AHP) multicriteria methodology, in Costa da Caparica (Portugal). The definition of the different criteria, as well as their respective weighting for the overall problem and index calculation, was carried out with the help of experts in the subject. By following this methodology, and by using Geographic Information Systems (GIS), hazard, vulnerability, and risk indexes were obtained. The most hazardous areas are located closest to the sea, where the elevation is the lowest, whereas the most vulnerable areas are in neighborhoods with specific socioeconomic characteristics (high urban and economic density). Overall, around 30% of the study area displays moderate to very high risk regarding the occurrence of overtopping and flooding events. The results of this study will be helpful in decision-making processes in matters of coastal zone management and monitoring.


Author(s):  
Timu Gallien ◽  
Marie-Pierre Delisle

Coastal flooding is a significant humanitarian and socioeconomic hazard (e.g., Nicholls, 2010). Global mean sea levels are expected to rise over the coming century and mean higher high water (MHHW) and mean high water (MHW), peak levels that drive coastal flooding, show upward trends in many locations (Mawdsley et al., 2015). Significant coastal flooding will occur by 2050 (e.g., Tebaldi et al., 2012; Sweet and Park, 2014). Wave overtopping is primary driver of coastal flooding. Low-lying urbanized sand spits, backed by an estuary are particularly vulnerable to sea level rise. Recent field observations suggest distinct feedbacks between wave overtopping, beach groundwater levels and backshore vulnerability.


Author(s):  
Jentsje van der Meer ◽  
Gosse Jan Steendam ◽  
Cesare A. Mosca ◽  
Luca Bolatti Guzzo ◽  
Koichi Takata ◽  
...  

A dike or levee will protect a polder to build in a tropical country against coastal flooding. To ensure that the performance of the dike is in accordance with the safety standard, wave overtopping tests with a wave overtopping simulator have been performed on a mock-up dike. These wave overtopping tests will guide the selection of the grass species and topsoil for the grass cover of the landward side of the dike. The paper describes the design of a new dedicated wave overtopping simulator, the construction of the mock-up dike, the results of the eight tests on the mock-up dike and the critical velocities (strength indicator of the grass cover) established with the cumulative overload method.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/MCuKojNyNyQ


Shore & Beach ◽  
2019 ◽  
pp. 29-35
Author(s):  
Michele Strazzella ◽  
Nobuhisa Kobayashu ◽  
Tingting Zhu

A simple approach based on an analytical model and available tide gauge data is proposed for the analysis of storm tide damping inside inland bays with complex bathymetry and for the prediction of peak water levels at gauge locations during storms. The approach was applied to eight tide gauges in the vicinity of inland bays in Delaware. Peak water levels at the gauge locations were analyzed for 34 storms during 2005-2017. A damping parameter in the analytical model was calibrated for each bay gauge. The calibrated model predicted the peak water levels within errors of about 0.2 m except for Hurricane Sandy in 2012. The analytical model including wave overtopping was used to estimate the peak wave overtopping rate over the barrier beach from the measured peak water level in the adjacent bay.


Author(s):  
Naoto HIGUCHI ◽  
Yoji TANAKA ◽  
Katsuyuki SUZUYAMA ◽  
Hidenori SHIBAKI
Keyword(s):  
New Wave ◽  

Author(s):  
Hajime MASE ◽  
Sooyoul KIM ◽  
Masatoshi YUHI ◽  
Masahide TAKEDA ◽  
Shinya UMEDA ◽  
...  

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