Storm-induced coastal risks at the Tordera delta under different climate scenarios

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Jose A. Jimenez, Marc Sanuy, Agustin Sánchez-Arcilla

Chair(s): dr. Vojinovic

Tuesday 30 june 2015

14:20 - 14:35h at Central America (level 0)

Themes: (T) Special session, (ST) Coasts at threat in Europe

Parallel session: 6H. Special session: Coasts at threat in Europe

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Storm-induced risk assessment is a critical issue for managing sedimentary coastal areas. It comprises the quantitative estimation of the induced processes/hazards (erosion and inundation) determining the magnitude of expected coastal land loss and extension of flood-prone areas, which can seriously condition the proper coastal management. Moreover, since land use planning is usually designed to have relatively long lifetimes (in the order of decades), it is important to assess potential variations in the magnitude of storm-induced hazards due to climate factors. In low-lying coasts, this is even more important due to its intrinsic sensitivity to the impact of these events. Within this context, the objective of this work is to assess storm-induced hazards (erosion and inundation) in the Tordera delta under different climate scenarios. It is a small cuspate delta located about 50 km northwards of Barcelona, behaving as a hotspot for coastal hazards at different time scales. During the last decades it has been experiencing long-term coastal erosion due to the decrease in river sediment supply. This has resulted in a progressive narrowing of the sedimentary coastal fringe, increasing the exposure of existing infrastructures. As a consequence, the induced damage has increased without a measurable increase in storminess, stressing the synergy between long-term and episodic scale hazards. The practical goal of this work is to delineate hazard (erosion and inundation) areas to help managers to make coastal planning decisions. To include potential climate-induced variations, storm-induced hazards will be assessed under present conditions and under different climate scenarios, covering the high end conditions from IPCC AR5. This will permit to bound the climate-induced uncertainty in delineating hazard areas.