Risk areas prioritization approach to support disaster management

a case study in Porto Alegre, Brazil

Abstract

Climate change has increased the frequency and intensity of climate disasters, impacting over social, environmental and economic dimensions. In this context, this study aims to develop a multicriteria approach to prioritize risk areas, supporting decision-makers in disaster mitigation strategies. The approach integrates social, economic, infrastructure, and physical criteria, selected via expert focus groups and weighted using a mathematical matrix based on the Analytical Hierarchy Process (AHP). The criteria’s weights, combined with local indicators, results in a prioritization index. The approach was tested in risk areas of Porto Alegre, Brazil. The results of the study highlighted social criteria as the higher weights, with 43.7% of importance, followed by physical (25.5%) and infrastructure (19.4%) dimensions, and at least the economic dimension (11.4%). The findings underscore the prevalence of social criteria, highlighting the vulnerability of populations in areas with inadequate infrastructure. That has resulted in higher prioritization indexes in extreme social vulnerability areas in Porto Alegre, especially in areas impacted by hydrological processes, such as floods and flash floods, reflecting the critical reality of recent events, such as the historic 2024 flood. By identifying priority zones, this approach serves as tool for guiding sustainable, resilient urban planning and for optimizing public investment.