Shoreline position change and the relationship to annual and interannual meteo-oceanographic conditions in Southeastern Brazil

Abstract

Historical satellite imagery datasets are commonly used to map coastal behavior over time while correlating it with concurrent meteo-oceanographic conditions. Thus, this study evaluates the shoreline position changes over 60 km of Rio de Janeiro southern coast (SE Brazil) using the integrated analysis of Landsat imagery (Landsat 5 TM and Landsat 8 OLI sensors) and a time series extracted from the WaveWatch III (WW3) model spanning the 1986–2018 period. This first study conducted in the area between the Marambaia barrier island and Recreio-Barra da Tijuca beaches aims to correlate morphological changes with wind wave climatology over a 30-year span. The verified interannual variability was particularly correlated with more energetic storm events and coastal erosion during La Niña years. These results agree with and reinforce previous conclusions highlighting an important teleconnection pattern that affects Southern hemisphere beaches. Overall, 18% of the coastline is under erosion, 52% is stable and 30% is advancing, values close to the global average. Moreover, the applied methodology can be easily replicated in any sandy coast around the world, especially where in situ observations are scarce, becoming an important tool for studying complex coastal systems.