Beach recovery capabilities after El Niño 2015–2016 at Ensenada Beach, Northern Baja California

Influence of storm sequencing on breaker bar and shoreline evolution in large-scale experiments

“…This beach response can result in sediment being stranded offshore beyond the depth of closure in a sediment compartment which is unavailable for beach recovery under low energy conditions (Scott et al, 2016;Baldock et al, 2017;Ruiz de Alegría-Arzaburu and Vidal-Ruiz, 2018;Biausque and Senechal, 2019). Despite not unusual in natural environments, in the present experiments a change in the active beach state was not observed and sediment eroded during storm conditions could still be mobilised for subequent recovery.…”

“…This sediment volume spreads between x ≈ -10 m and x ≈ -2 m and it supplies the evolving berm resulting in a reflective beach state. Onshore transport of the bar sediment under long periods of low energy wave conditions has also been reported from field measurements(Phillips et al, 2017;Ruiz de Alegría-Arzaburu and Vidal-Ruiz, 2018). In addition,Phillips et al (2017) and Ruiz de Alegría-Arzaburu and Vidal-Ruiz (2018) reported welding of the bar to the shoreline and highlighted the importance of the proximity of the bar to the shoreline for shoreline recovery.Even though in the present study the proximity of the breaker bar to the shoreline cannot clearly be linked to beach recovery and welding of the bar to the shoreline is not observed, onshore transport of the bar sediment under low energy conditions clearly takes place and the sediment is important to supply the formation of the berm, to recover the shoreline and to form a reflective beach profile.Reflective beaches typically develop under wave conditions with very low Ω with the following characteristic features(Wright and Short, 1984;Short, 1999): an (almost) barless profile; a steep and relatively linear beach face with a runnel (the beach slope at the offshore side of the berm was 1/8 which is considerably steeper than the 1/15 slope of the initial profile); step formation at the base of the beachface (corresponding to the maximum run-down location which was observed to be located at -1.8 m during the last A3 test, see figure5b); and cross-shore sediment sorting with accumulation of coarser sediments around the step and deposition of finer sediments offshore of it.…”

“…Other studies, such as Ruiz de Alegría-Arzaburu and Vidal-Ruiz (2018), reported that, because of severe beach erosion and offshore sediment transport into larger water depths than usual during winter months, subsequent summer wave conditions were unable to fully recover the beach. This implies that a minimum level of wave energy is required to mobilise sediment that was transported far offshore during high energy storms (Scott et al, 2016;Ruiz de Alegría-Arzaburu and Vidal-Ruiz, 2018;Biausque and Senechal, 2019).…”

El Niño‐Southern Oscillation Impacts on Global Wave Climate and Potential Coastal Hazards

“…The investigation of the effects induced by ENSO has become of key interest in medium and long term coastal management (Barnard et al., 2015, 2017; Escudero et al., 2019; Medellín & Torres‐Freyermuth, 2019; Mortlock & Goodwin, 2016; Ruizde Alegría‐Arzaburu & Vidal‐Ruiz, 2018; Storlazzi & Griggs, 1998; Storlazzi & Reid, 2010) due to its impact on coastal risk, wave power extraction and coastal ecosystem responses. The results presented here give an insight into global patterns of interannual variability of wave direction and wave power driven by ENSO, as one of the primary climate‐related drivers of basin‐wide coastal vulnerability (Barnard et al., 2015; Morim et al., 2019).…”

“…Previous work has demonstrated that the vulnerability of Pacific coasts is dominated by ENSO (Barnard et al, 2015;Goodwin, 2005;Ruiz de Alegría-Arzaburu & Vidal-Ruiz, 2018;Silva et al, 2017). Moreover, many studies have been carried out to identify the wave climate response to ENSO at a global scale (Mori et al, 2018;Reguero et al, 2015Reguero et al, , 2019Semedo et al, 2010;Stopa & Cheung, 2014).…”