Modelling storm responses on a high-energy coastline with XBeach

Abstract

The XBeach model has been used to simulate the morphological impacts of storms on sandy and gravel beaches. Taking as a case study Rossbeigh Spit located on the high-energy coast of western Ireland, the study reported here tests the capacity of XBeach to reproduce barrier breaching during a storm in December 2008. It demonstrates that predictions of the breaching event agree reasonably well with observations. However, the main focus of the paper is to establish using the model results, sitespecific critical wave and water level conditions giving rise to dune erosion, overwashing and breaching. By deriving simple-to-use expressions to define hydrodynamic thresholds the study advances the ability to predict the impacts of infrequent and rarely observed storm events and is considered to provide useful coastal management tool for assessing the vulnerability of sandy barriers to breaching high-energy during storms.

Modelling Long-Term Morphodynamics in Practice: Uncertainties and Compromises

“…Predictions of the breaching event morphodynamics by XBeach demonstrated reasonably agreement with the observations (Williams et al, 2015). However, as is frequently the case in most coastal studies of this nature, the data describing the hydrodynamics, waves and the bathymetry and topography were incomplete and recourse to hindcast data and varied data sources to establish the pre-and post-storm bathymetry was required.…”

A geo-spatial study on spatio-temporal growth of brackish water aquaculture along the coastal areas of West Bengal (India)

“…As a result, brackish water aquaculture is being popular over rice cultivation for high returns. It has been reported that the rapid expansion of coastal aquaculture in India is responsible for landscape transformation, such as mangrove deforestation and loss of agricultural land (Vadlapudi 2003;Hein 2000;Hossain et al 2002;Rajitha et al 2007). Recent studies revealed that the landuse/landcover along the coastal border of West Bengal is being changing rapidly mainly due to the mushrooming of aquaculture firms (Mitra and Santra 2011;Samanta and Hazra 2012).…”

Managing coastal environments under climate change: Pathways to adaptation

“…Whilst the Inch Spit appears to be relatively stable today, Rossbehy was breached by a storm surge in 2008. The loss of dune volume reached a maximum of 530,000 m 3 /yr in 2008 and culminated in the 13-14 December 2008 breach which left a small northern island at around 500 m from the southern dune systems at high water (Williams et al, 2015). Henceforth, the erosion rates continue at rates of 30-50 m/yr along its core-length and at circa 25 m/yr on the seaward shore face, with the breach doubling in size to 1400 m width from 2012-2014.…”

“…Breaching events will likely become more frequent in response to rising sea levels due wave action at higher elevations across beach and dune profiles (Williams et al, 2015). Under future SLR associated to climate warming (about 0.8 m SLR by 2100 for the RCP 8.5, see Section 3) this structure may disintegrate, with significant impacts on Inch and the morpho-hydrodynamics of neighbouring coastal systems, though the barrier may reform in part or possibly move further east on land (Church et al, 2013;O'Shea and Murphy, 2013;Devoy, 2015a).…”

“…These fragile environments are highly affected by extreme events Gracia et al, 2013a;Williams et al, 2015). However, overwash episodes can lead to accretion Sanchez-arcilla et al, 2015b) that results beneficial for the mid to long term sediment budget.…”