La morfodinámica de playas arenosas y la gestión de unidades de conservación: el caso de la playa de fora, Itapuã, RS

Abstract

Analysis of beach morphodynamics is a power ful tool to government managers dealing with environmental resources. This work describes the morphodynamic and sediment characteristics of the praia de for a, one of the beaches of the itapuã state park (RS, Brazil). The main goal of this study is to present scientific data to help managers to understand the environment in their decision making process. The models of wright & short (1984) and short. & Aagaard (1993) were applied to describe the shoreline changes. The results indicate a beach presentation great annual variability as shown by large changes on beach width (from 1.8 to 18 m) and beachface steepness (from 1° to 13°), oscillation between the intermediate and dissipative morphodynamic state, bidirectional alongshore sediment transport, present of erosion and accretion in adjacent beach profile segments with different rates of sediment transport. These results were used to define criteria of decision making in the following; (1) assess risk and safety for swimmers, (2) restrict permits of sand mining, (3) limit the park s submersed area.