Análise espacial de risco e vulnerabilidade a eventos de tempestade na Orla de Itaipuaçu, Maricá-RJ: um enfoque nas características geomorfológicas da Barreira Holocênica e no processo de ocupação

Abstract

This dissertation focuses on the spatial analysis of areas vulnerable to storm events on the coast of Itaipuaçu, Maricá (RJ), a coastal region exposed to high-energy waves. The main objective of this study is the spatial analysis of areas vulnerable to storm events on the Itaipuaçu coast in 2020, as well as explanatory elements for understanding coastal processes, in order to contribute to coastal planning and management. The research encompasses a thorough assessment of land occupation, examining landscape transformations between the 1970s and 2020, through historical aerial photographs, and based on surveys using High Resolution Images (ARP). The susceptibility of the study area to extreme metoceanographic events is quantified and hierarchical using land use data, literature review, Digital Terrain Models (DTM) and field analyses. The integrated analysis of vulnerability to storm events, with the application of fuzzy logic and high-resolution georeferenced data, is conducted at a detailed scale. The results reveal that the Itaipuaçu waterfront is undergoing an occupation process, with a moderate density of recent constructions and occupations. Of the seven indicators evaluated for susceptibility to coastal storm events, three were classified as high susceptibility, three as moderate susceptibility, and only one indicator as low susceptibility. The vulnerability assessment along the coastal stretches of Itaipuaçu reveals levels classified as very high, high and medium in Recanto de Itaipuaçu, as well as in a stretch where sheet piles were installed to contain storm surges. Areas with residences on top of the barrier, absence of vegetation on the coastal strip, low altitudes and the presence of rigid engineering structures facing the sea are emphasized in this context, due to the potential impact on local sedimentary dynamics. As we move towards the east of the coast, towards the Maricá Environmental Protection Area, vulnerability gradually decreases. Finally, the work can contribute to identifying priority areas to implement adaptation and risk reduction policies on the Itaipuaçu Coast, especially considering the imminent threats related to climate change, which could intensify extreme coastal storm events.