LAUSR

ABSTRACT Ferreira, C.; Silva, P.A.; Fernández-Fernández, S.; Baptista, P.; Abreu, T.; Romão, S.; Fontán-Bouzas, A.; Bertin, X., and Garrido, C. 2018. Wave Climate Definition on Modeling Morphological Changes in Figueira da Foz Coastal System (W Portugal). In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp.1256–1260. Coconut Creek (Florida), ISSN 0749-0208. Field surveys at Figueira da Foz coastal system, a jettied river-mouth located to the W of Portugal, show a high impact of storm events on the morphological evolution of the ebb-tidal delta, with formation of a submerged sandbar and the quick infill of dredged areas. Non-stormy wave conditions produce minor morphological changes. The morphodynamic modeling of this system is being done to support coastal management. The methodology uses Delft3D modeling system that was previously calibrated for this coastal region. Modeling scenarios are set by considering two initial bathymetric situations, i.e., with or without an excavation site resulting from dredging operation. In order to investigate the relations between the computational efficiency and the time series of the input wave data, some tests were performed including a month with a total of 70% of storms and other with 10%, approximately. For each period it was studied the whole month period and only the storms. Numerical results disclose similar patterns of morphological evolution for both complete and storm periods simulated. Nevertheless, the omission of lower wave energy conditions slightly covers up the volume of sediment accretion in the area. This volume of sediment accretion masking effect is higher in the dredging case study, since dredged area acts as a sink of sediment. The results demonstrated that morphodynamic simulations should include the whole set of waves recorded to achieve more accurate estimations of sediment transport rates and corresponding sediment balance.