Coastal littoral dynamics of Tres Arroyos and San Cayetano, Buenos Aires

Abstract

Coastal erosion ofBuenos Aires Province is originated in general by natural causes, but sometimes is produced by antropic causes. In San Cayetano y Tres Arroyos counties, coastal problems are concentrated in touristic villages and their beaches. Dunes fixation in Balneario San Cayetano or their afforestation in Claromecó, Reta and Orense, have provoked significant sand accumulation on top of former cliffs, the obstruction of some small in lets and the dissactivation of dune ramps (from beaches to the top of the cliffs). By the mean of morphologic and sedimentologic characterizations the worse impact sites were identified. Due to grass colonisation, transverse dunes have changed into parabolic profiles. However, dune fixation problems remain in Balneario San Cayetano and Dunamar in Claromecó. Tres Arroyos beaches are the most extended of this coastline, and particularly in Claromecó present more sand variability. At the inlets of the Quequén Salado and Claromecó creeks, and the interval between the Cristiano Muerto creek and Balneario San Cayetano, the greater variations of the coastline were surveyed. Comparing grain-size samplings spanned 45 years between them, no significant beach changes in the sand were recognised.