A temporal waterline approach to mapping intertidal areas using X-band marine radar

Using Random forest and Gradient boosting trees to improve wave forecast at a specific location

Multihazard simulation for coastal flood mapping: Bathtub versus numerical modelling in an open estuary, Eastern Canada

Understanding and predicting the temporal variability of sediment grain size characteristics on high-energy beaches

Assessing the impact of extreme storms on barrier beaches along the Atlantic coastline: Application to the southern Rhode Island coast

The storm impact scale of Sallenger (J Coast Res 890–895, 2000) was tested on a partially engineered beach. This scale is supposed to provide a convenient tool for coastal managers to categorize the storm impact at the shore. It is based on the relation between the elevation of storm wave runup and the elevation of a critical geomorphic or man-made structures in the present study. Two different approaches were tested to estimate the elevation of extreme storm wave runup: (1) a parametric model based on offshore wave conditions and local beach slope and (2) the XBeach process-based model that solves implicitly the runup. The study shows comparisons between impact regimes computed with the two methods and those derived from video observations acquired during 2 weeks while the site was battered by three consecutive storms. Storms scenario including wave conditions with higher return periods and different tidal range were also investigated. The advantages and disadvantages of the two methods used to compute extreme water level are then compared, and guidelines for the development of early warning system are drawn.

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A comparative study of models to predict storm impact on beaches

De Santiago, I., Morichon, D., Abadie, S., Castelle, B., Liria, P. and Epelde, I., 2013. Video observation of the morphodynamics of nearshore sandbars on a partially engineered embayed beach. Embayed beaches are prevalent environments along the northern Spanish coastline. The present work analyses the temporal and spatial variability of nearshore sandbars on the pocket beach of Zarautz using daily video observations over 2 years. This partially urbanized beach can be divided into two well defined distinct areas: a natural section backed by a sand dune system to the East and an engineered section with rigid seawalls to the West. The objective of the present work is to evaluate if the engineered and natural sections of the beach present different morphological behaviors. The video image analysis was performed in two steps: First, sand bars were characterized visually and classified following standard classification schemes. Then, the outer sand bar migration was measured using automatic bar detecti...

https://bioone.org/journals/journal-of-coastal-research/volume-65/issue-sp1/SI65-078.1/Video-monitoring-nearshore-sandbar-morphodynamics-on-a-partially-engineered-embayed/10.2112/SI65-078.1.pdf

Video monitoring nearshore sandbar morphodynamics on a partially engineered embayed beach

Morichon, D.; de Santiago, I.; Delpey, M.; Somdecoste, T.; Callens, A.; Liquet, B.; Liria, P., and Arnould, P., 2018. Assessment of flooding hazards at an engineered beach during extreme events: Biarritz, SW France. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 801–805. Coconut Creek (Florida), ISSN 0749-0208.This study focuses on flooding hazards along the Grande Plage of Biarritz. This pocket engineered beach, located in the south west of France, was highly battered by a series of storms during the winter 2013–2014 and experienced great damages to buildings and infrastructures. The vulnerability of this type of beaches to storm impact is assessed using the XBeach surf beat model. For validation purpose, a dedicated spectral wave model is also used on the coastal area to force XBeach at 15 m depth. This coastal wave model is first validated against nearshore wave measurements provided by two sensors deployed during the winter 2017. Then the total water level elevations measured at the shore with a video monitoring system are used to assess XBeach results. The model is then used to run a series of extreme storm scenarios with different return periods (1, 10 and 50 years). Results show how the occurrence of flooding events increases with storm intensity. The response of the beach is alongshore non-uniform for all the storm scenarios. The section, where the dry beach width is smaller, is more exposed to flooding whereas vulnerability is reduced by wider dry beach areas. This study constitutes a milestone and outlines next steps toward the development of an operational warning system for the GPB.

Assessment of Flooding Hazards at An Engineered Beach during Extreme Events: Biarritz, SW France

Ondarreta Beach is one of the most emblematic and visited beaches in the Basque Country. This beach is part of La Concha bay, with Santa Clara Island in the middle of the bay and a semi submerged dike and reef in front of it. The combination of this morphology together with the tidal range in the area (max. springs 4.6m) results in a very particular wave climate. The beach contains different strata of sand, natural rocks and the remains of artificial structures. Therefore, rocks sometimes appear at the surface, depending on the changes of the beach profile. This situation harms the normal use of the beach and can be a risk for the users. During recent years this process has increased and, especially in the summer, a big part of the intertidal profile of the West part of the beach shows a gravely and rocky profile. In 2003, the town council of San Sebastian entrusted AZTI Foundation with the study of this beach. For this purpose AZTI planned the data analysis and the morphodynamic study of the evolution of the beach in three different time scales, in order to clarify whether the recent problems at the beach are an increasing erosive process, or part of a natural cycle. The three different time scales of analysis of morphodynamic processes taking place in this beach are: - Short term scale: wave data measurement and analysis, modeling of wave, current and sediment transport. - Medium term scale: analysis of seasonal equilibrium shape and profile. - Long term scale: analysis of morphodynamic evolution of the whole system (the bay). This analysis has contributed to the management of the beach, implying artificial seasonal sand movements, trying to encompass the natural processes and shoreline protection with the recreational use of the beach.

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Pedro Liria

Papers

A comparative study of models to predict storm impact on beaches

Video monitoring nearshore sandbar morphodynamics on a partially engineered embayed beach

Assessment of Flooding Hazards at An Engineered Beach during Extreme Events: Biarritz, SW France

Morphodynamic study of the Ondarreta Beach in San Sebastian (Spain)