Coastal Vulnerability Index revisited: a case study from Maricá, RJ, Brazil

Abstract

The Brazilian coast is over 7000 kilometers long with many different ecosystems. Among these, are the beaches, dominated by the high dynamism caused by the action of oceanographic agents (tides, waves and currents). Human occupation of the coast for living, and the economic use of the coast (ports, tourism, fishing), increase the possibility of damaging this ecosystem. Coastal vulnerability studies are an important tool for the management of these areas, predicting how an environment can cope or recover from extreme events, for example, the rising sea level. This study aims to improve vulnerability evaluation of coastal areas, contributing to a more efficient, accountable and sustainable coastal management. To test the concept, an area at coastal Maricá, a municipality in Rio de Janeiro State, Brazil, was used. This coastline is comprised of a long sandy beach limited by rocky coastal shores. A vulnerability index was calculated from GIS data analysis of geomorphology, coastal slope, shoreline migration, tidal range, maximum height of the waves, sea level change scenario evaluation, dune height, and urban density variables for the various coastline sectors. About a third (34.69%) of the coasts have very high vulnerability, while have 34.03% high vulnerability, 25.33% have moderate and 5.95% have low vulnerability. Results obtained contribute to the planning and management of the study area, providing a tool for local environmental analysis, and establish a ranking of priorities for public action, based on different levels of vulnerability found to shoreline of Maricá.