Longshore Sediment Transport Estimation at Areão Beach (NW Portugal) under Climate Change Scenario

Fernández-Fernández, S.; Silva, P.A.; Ferreira, C.C., and Carracedo-García, P.E., 2020. Longshore sediment transport estimation at Areão Beach (NW Portugal) under climate change scenario. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. (Seville, Spain). Journal of Coastal Research, Special Issue No. 95, pp. 479-483. Coconut Creek (Florida), ISSN 0749-0208.The knowledge of longshore sediment transport is essential to understand coastal systems morphological evolution, and consequent erosion/accretion processes. This research is focused on Areão Beach, a groined sandy beach, located southwards of Aveiro Lagoon (NW Portugal). The high energetic wave climate and coastline orientation induce a substantial southward net sediment transport rate. Nevertheless, this transport is interrupted by coastal defense structures resulting in erosion problems downdrift. Future changes in wave and storm climate can alter current patterns of coastal erosion. This contribution aims to characterize the longshore sediment transport rate under a future wave climate scenario. The Delft3D-WAVE module propagated wave spectral data for historical and future, corresponding to climate change scenario RCP8.5. The hydrodynamic parameters (significant wave height, peak wave period and wave direction) were extracted at offshore Areão Beach and linear wave theory was applied to obtain significant wave height and wave direction at breaking point. Then, CERC empirical sediment transport formula re-evaluated in 2013 was used to estimate longshore sediment transport values. The results disclose a change in the magnitude of longshore sediment transport and an intensification of northwards transport in the future. These findings can contribute for an adequate decision-making regarding beach erosion management.