Present and future flooding and erosion along the NW Spanish Mediterranean Coast

Abstract

Coastal flooding and eros-ion caused by extreme events are the main factors responsible for beach hazards. This effect will be exacerbated by the sea level rise induced by climate change. The present work determines the vulnerability to erosion and flooding along 55 beaches grouped in different coastal archetypes, representative of the Catalan coast. The vulnerability assessment has been done through the numerical simulation of different combinations for projected waves and mean water levels under present conditions and the climate change scenarios RCP4.5 and RCP8.5 for the year 2100. A storm event approach has been used to determine coastal flooding and erosion with return periods of 50, 100, and 500 years using the XBeach numerical model. Results show that shoreline retreat is not the best proxy to characterize the erosion. The low-lying nature of the coast, the non-presence of well-developed berms, and the existence of river mouth and torrents govern the coastal flooding. The sea level rise appears to be a dominant variable in coastal hazards.

Coastal Adaptation Pathways and Tipping Points for Typical Mediterranean Beaches Under Future Scenarios

“…These projections, combining biophysical and socio-economic variables, are used to prepare adaptation pathways under climate change [45], supported by a combination of observations and simulations at different scales [46][47][48]. Future wave storm features have been inferred from data [49,50] coming from the network termed XIOM (Xarxa d'Instrumentació i Observació Marítima de la Generalitat de Catalunya), now discontinued, and from the Puertos del Estado network that combines buoys and forecasts [48]. The selected significant wave height levels are shown in Table 1, where all storms come from NE, which is the dominant direction for energetic wave storms in this part of the Western Mediterranean.…”

“…These interventions have been tuned according to local experience (social and technical memory) and projected climates, with a minimum beach width of 20 metres to ensure the protection and touristic functions. These state-of-the-art interventions [51] consider local constraints and history as manifested by stakeholders and are prioritised according to effectiveness based on local experience and numerical simulations [50]. Their sequencing along adaptation pathways requires monitoring and a maintenance programme, where the proposed interventions will be adapted to maintain risk reduction in spite of the uncertainties in future climatic and management conditions.…”

Coastal Adaptation Pathways and Tipping Points for Typical Mediterranean Beaches under Future Scenarios

“…Future wave storm features have been inferred from data [52,53] coming from the network termed XIOM (Xarxa d'Instrumentació i Observació Marítima de la Generalitat de Catalunya), now discontinued, and from the Puertos del Estado network that combines buoys and forecasts [31]. The selected significant wave height levels are shown in Table 1, where all energetic storms come from NE, which is the dominant direction for large wave storms in this part of the Western Mediterranean.…”