Morfological changes on Araçá Bay: implications on its dynamics

Abstract

Coastal environments altered by anthropogenic activities are quite common on the Brazilian coast, and results in impacts on its dynamics often unknown. This project aims to analyze changes that have occurred over the past decades in the Araçá Bay (São Sebastião , SP ) mainly due to an area reduction. Since the 70's, approximately 30% of the Bay area was grounded, probably leading to changes in its dynamics and material exchanges with the São Sebastião channel. The Araçá Bay, due to be sheltered from the waves, can be defined as a tidal flat, with shallow and wide intertidal area with a predominance of fine sediments. The analysis of the morphological changes of the coastline and area of the Bay will be conducted through the use of satellite images (Landsat) available since 1973. Assessment of the change in the hydrodynamics of the system will be accomplished through the inclusion of these modifications in a validated hydrodynamic model for the region. Thus, will be possible to understand how hydrodynamic processes have been modified over time and evaluate the impacts of these changes in the material exchange between the bay and adjacent coastal areas.