Sistemática para análise de risco de áreas suscetíveis à inundação

Abstract

The concept of flood risk has evolved over time, incorporating different dimensions that make it more comprehensive and applicable to disaster management. In this context, this study adopts the hierarchical framework proposed by Sayers et al. (2013), which defines risk as a combination of probability of occurrence, exposure, and vulnerability. Thus, the main objective of this dissertation is to develop a systematic approach for flood risk analysis to support decision-making, considering physical and socioeconomic aspects in Brazilian sub-basins. To this end, criteria and indicators were selected and weighted to represent the three dimensions of risk. Hazard indicators include variables such as the number of days with precipitation above a certain threshold, precipitation intensity, topographic wetness index, and flow accumulation. Exposure indicators cover land use and occupation, population density, and critical infrastructure; whereas vulnerability was represented by socioeconomic variables, such as age distribution, access to services, and literacy. The weighting of indicators was performed through expert consultation, using a participatory technique for variable ranking. The methodology was applied to the Nascentes sub-basin, identifying higher-risk areas in Cachoeira do Campo, Amarantina, and upstream of the Rio de Pedras reservoir. The validation, performed in comparison to ANA’s Flood Vulnerability Atlas, revealed a divergence in the Rio das Velhas section, indicating that the methodology captured nuances distinct from ANA's approach. Despite this difference, the systematic approach proved effective in identifying risk areas. Finally, refining the model's sensitivity in rural zones is recommended for future studies.