ÁREAS DA BACIA HIDROGRÁFICA DO RIO MOCAMBO SUSCETÍVEIS A INUNDAÇÕES, NA CIDADE DE URBANO SANTOS, ESTADO DO MARANHÃO – BRASIL

Abstract

Flooding is one of the natural disasters that most affect populations worldwide. It can be understood as the process in which water overflows from the drainage channel into marginal areas—such as floodplains, wetlands, or the exceptional high-water bed—when water levels exceed the maximum height of the river’s main channel. Floods, although natural hydrological phenomena, become disasters when they impact vulnerable populations, causing severe socioeconomic damage and a high number of victims, especially in developing countries. This study begins with the recognition that, although the Atlas of Flood Vulnerability (ANA, 2014) classified a tributary of the Mocambo River as having low flood vulnerability, recent records indicate overflow events and localized impacts, underscoring the need for a more detailed analysis at the local scale. Accordingly, the main objective was to analyze the flood susceptibility of areas within the Mocambo River basin in the city of Urbano Santos. Methodologically, the research was grounded in the hypothetico-deductive method and supported by bibliographic investigation, fieldwork, physiographic analysis, morphometric parameters, and geotechnologies, including geoprocessing and remote sensing, which enabled the production of thematic maps. The results revealed that the basin exhibits low natural susceptibility to flooding, with indices comparable to lower-risk basins. However, specific situations of vulnerability were identified, driven by irregular occupation of riverbanks and the socioeconomic fragility of populations residing near the watercourse. Thus, the study found that natural susceptibility alone does not account for the complexity of the problem; social vulnerability and inadequate land use are decisive factors in amplifying flood risk. This research contributes to strengthening the geographic understanding of socio-environmental risks by integrating physical and social variables, and it provides relevant insights for the formulation of public policies aimed at territorial management and the mitigation of flood impacts. Furthermore, it highlights the importance of incorporating the obtained data into urban planning instruments, such as master plans and zoning regulations, as well as the need to reinforce Civil Defense structures and early warning systems. The study concludes that, even in basins classified as having low susceptibility, risks cannot be disregarded—particularly in a context of climate change and social inequalities—reaffirming the role of geographical science in building more resilient territories.