Journal of Coastal Research, Special Issue No. 61, 2011 328 Journal of Coastal Research SI 61 328-334 MCRR3-2010 Conference Proceedings 2011 Coastal Erosion Management in Algarve (Portugal) – a Beach Nourishment Case Study Bárbara Proença 1 , Filipa S. B. F. Oliveira 2 , and Francisco Sancho 3 ABSTRACT PROENÇA, B., OLIVEIRA, F.S.B.F and SANCHO, F., 2011. Coastal Erosion Management in Algarve (Portugal) – a Beach Nourishment Case Study. In: Micallef, A. (ed.), MCRR3-2010 Conference Proceedings, Journal of Coastal Research, Special Issue, No. 61, pp. 328-334. Grosseto, Tuscany, Italy, ISSN 0749-0208. In the Portuguese southern coast, national and international appeal turns it into a highly relevant area concerning the country’s economy. Vale do Lobo is a resort located in the centre of this coast, where the beach has been suffering from erosion problems for several years now. Local interventions have been executed in order to prevent the erosion of the beach, yet the efficiency of such strategy has not been verified. This study’s main purpose is to enable a better understanding of the evolutionary trends of the coastline between the Quarteira and Ancão inlet and to analyse the efficiency of the beach nourishment interventions as a protection technique for a coastal environment with the wave energy exposure and geomorphologic characteristics of the present one. The study focussed on a 10-year period, during which, 700x10 3 and 370x10 3 m 3 of sand with D50=0.76 mm (slightly larger than the D50 of the native beach) were extracted from offshore, and deposited in the foreshore. The wave climate in the study area was processed, analysed and used as input for modelling the nearshore processes. In addition, beach profiles measured alongshore have been analysed to obtain the representative beach profile. Coastlines of different dates have been derived from aerial photographs. The longshore transport model Litdrift and the coastline model Litline were applied to study the sediment dynamics. Litdrift was used to estimate the longshore transport capacity of the beach for the hydrodynamic series considering the representative beach profile previously obtained. These results were then used to calculate the evolution of the coastline due to the incident wave climate with Litline model. Aerial photographs were used to verify the model. The analysis of the two beach nourishments performed allowed inference on the efficiency of this coastal protection technique to delay the erosion process. ADDITIONAL INDEX WORDS: beach nourishment, coastal erosion, coastal protection, coastline evolution, Portuguese coast. INTRODUCTION Beach erosion is of great concern in the present due to its economical impacts on the tourism industry. This is a problem that, according to Phillips and Jones (2006), could likely be intensified with climate change which is predicted to be translated in both increasing of storm activity and sea level rise. DOI: 10.2112/SI61-001.1 received XX; accepted XX ©Coastal Education & Research Foundation 2011 Hard engineering structures such as groynes and breakwaters, for instance, have been traditionally used to fight erosion, but a growing number of authors see those as displacement of the problem from one location to the other (e.g. Castelle et al., 2009; Hamm et al., 2002) because they consist in an interruption to the littoral sediment drift (Taborda et al., 2005). Thus, soft protection measures, such as artificial beach nourishment, have been gaining relevance in the mitigation of coastal erosion problems. Hanson et al. (2002) conducted a study under the European project SAFE (Performance of Soft Beach Systems and Nourishment Measures for European Coasts) that compiled information concerning beach fill operation for coastal ϭ Laboratório Nacional de Engenharia Civil, Av. Brasil 101, 1700-066 Lisboa, Portugal Tel: + (351) 218443429 bproença@lnec.pt 2 Laboratório Nacional de Engenharia Civil, Av. Brasil 101, 1700-066 Lisboa, Portugal Tel: + (351) 218443457 foliveira@lnec.pt www.cerf-jcr.org 3 Laboratório Nacional de Engenharia Civil, Av. Brasil 101, 1700-066 Lisboa, Portugal Tel: + (351) 218443664 fsancho@lnec.pt