WIND-WAVE CLIMATE CHANGE AND INCREASING EROSION IN THE OUTER RÍO DE LA PLATA, ARGENTINA

SIMIONATO, C. G.; CODIGNOTTO, J.; DRAGANI, W. C.; MARTÍN, P.B; MEDINA, R.A.; ALONSO, G.

Sesimbra

Congreso; ECSA 54 - Coastal systems under change: tuning assessment and management tools; 2014

Centro de Oceanografia, University of Lisboa, Portugal y Estuarine and Coastal Sciences Association

The coastal area of Samborombón Bay ends in a short cliff which, during the last decades, has been undergoing an increased retrogression of approximately 8.2 m per decade. The aim of this work is to investigate whether this accelerated erosion can be related to an apparent wind-wave climate change, which has been recently reported for the Río de la Plata region. A numerical study with SWAN wave model for the period 1971-2005 drives to positive trends in the frequency of occurrence and heights of waves propagating from the E and ESE. Particularly, the number of cases of high waves from those directions displays a significant increment. In addition, previous papers have reported an increment of the frequency, height and duration of the storm surges in the Río de la Plata, so as a rise of the mean sea level in the region. It is concluded that the combination of those three factors acting together constitutes a powerful and effective mechanism which is likely responsible for the observed increasing erosion in Samborombón Bay.