Vulnerability to beach erosion based on a coastal processes approach

摘要

Erosive processes on coasts cause several socioeconomic and environmental losses. Understanding the vulnerability to erosion is fundamental to deal with its consequences. We assess the beach vulnerability to erosion based on environmental indicators. The study area for the present application is in Guaruja, a coastal zone of the state of Sao Paulo, where the vulnerability of six beaches was evaluated. The indicators used for the vulnerability assessment are: terrain elevation, wave exposure, power and angle of wave incidence and wave run-up. Regarding the wave climate of the region, the most frequent waves are those of the southern, eastern and southeastern quadrants. Significant wave heights are more frequent in the range of 1.0-1.5 m, and the most frequent wave periods are between 8 and 10 s. Perequa, Enseada, Asturias and Pernambuco beaches present low vulnerability and the Pitangueiras and Mar Casado beaches present moderate vulnerability. The study provides an interesting perspective for the management of coastal resources in the Guaruja region and similar coastal areas. In addition, although the analyzed beaches presented low and moderate vulnerability, processes such as climate change or inadequate interventions on adjacent beaches may negatively influence the studied region.