The magnitude of the wave runup is based on a number of contributing factors that have been the subject of numerous studies and a variety of research activities. Consequently, several parametric formulations already exist that can estimate runup magnitude in a variety of coastal conditions. However, the effect of swash-swash interaction and swash infiltration is not explicitly quantified in these existing parametric formulations. The current research aims to elucidate on one key aspect, namely, the effect of bed permeability on swash magnitude. Specifically, the aim is to find a relationship between infiltration rates and the maximum runup on the beach face. A series of experiments were performed at the Coastal Flume located at UCL, London, UK to characterize this effect of bed permeability on wave runup magnitude. The results from the series of experiments conducted favour a Hunt-type runup formulation and indicate that there is a clear relationship between bed permeability and the maximum wave runup. Other complicating factors make comparison to existing parametric formulations difficult and these will be discussed fully in the main paper.

No abstract

No abstract

Many low‐lying coastlines are exposed to overwash and marine flooding during large storm events, and the role of coastal ecosystems in reducing these hazards has been increasingly investigated and reported. This paper deals with the assessment of processes involved in coastal flooding over 2 years and 10 months at Anse Maurice, a reef‐fringed pocket beach located in Guadeloupe Island, in the Caribbean region. Daily maximum marine inundation was assessed using a fixed video system, and a hydrodynamic measurement campaign was organized to monitor local wave transformation through the reef system. The results show that daily highest runups (dHRs) are not linearly correlated with storm events since storm runup intensity is highly modulated by (a) the steric‐induced annual periodicity of sea level which showed minima in April and maxima in September and (b) the tidal level which influenced shortwave propagation on the reef flat (RF). These variables determined the reef submergence, an important parameter involved in wave transformation over reefs. Consequently, different runup responses existed for similar incident wave conditions, but generally wave attenuation ranged between 50% and 80%. Low‐frequency waves were found to dominate the hydrodynamics on the RF for the most intense wave conditions. The upper beach vegetation also reduces the maximum swash excursion at the beach between 1.7% and 42.8% for the observed storms, and thus reduces the potential for back beach flooding. This study demonstrates new comprehensive elements on runup behavior and nearshore processes, at different time scales, on reef‐lined beaches.