Variabilidade Espaço-Temporal da linha de costa do Rio Grande do Sul
This source preferred by Luciana Esteves
Authors: Slomp Esteves, L.
Editors: Muehe, D.
Publisher: Ministerio do Meio Ambiente
Place of Publication: Brasilia, Brazil
Patterns of shoreline change in the state of Rio Grande do Sul (RS) are described using kinematic DGPS surveys obtained from 1997 and 2002. The application of kinematic DGPS to map the 618 km of the RS coastline allowed the identification of seasonal and annual patterns of shoreline change at an unprecedent spatial and scale. The results show regional differences in the magnitude and in the pattern of seasonal and anual shoreline displacements, and also indicate that the shoreline returns to a previous position in different time scales in the three major sectors of the RS coast. Along the southern sector, the shoreline responds differently south and north of Albardão lighthouse, an area of a significant change in the coastline orientation. North of Albardão, the annual displacements of the shoreline indicate accretion with maximum magnitudes around 100 m. South of Albardão, the shoreline moves seaward in one year and northward in the following year with displacements not reaching 40 m. Along the central sector, changes in the shoreline position are the greatest in the state with magnitudes around 150 m. The annual shoreline changes along the central sector show an rhythmic pattern where accreting and eroding areas are intercalated and move to opposite directions in consecutive years. Along the northern sector, shoreline movements also show an opposite and rhythmic pattern and magnitudes of changes are variable alongshore. However, in this sector movements are dominantly seaward in one year and landward in the following year.