Hydrogeomorphological Characterization and Flood Vulnerability in A Coastal Watershed: Socioeconomic and Environmental Implications

Objective: The aim of this study is to identify areas potentially vulnerable to flooding events through multicriteria analysis, based on hydrogeomorphological variables and land use. Theoretical Framework: The relationship between humanity and landforms has shaped the occupation and use of space, with human activities altering physiography and disrupting natural processes. Geomorphology is essential to understanding the interaction between natural factors and human activities. Uncontrolled urban growth leads to environmental degradation and ecosystem overload, exacerbated by climate change. In Macaé (RJ), expansion driven by the oil industry has led to the irregular occupation of estuarine and flood-prone areas, increasing risks for the population. This scenario calls for studies that integrate geomorphology and hydrology to understand risk dynamics in watersheds. Method: In addition to hydrogeomorphological characterization, a multicriteria analysis was conducted, involving land use data, slope, and accumulated flow from the coastal watershed, and potential flood-prone areas and populations were analyzed. Results and Discussion: The results revealed that around 77% of the basin's coastal plain is at moderate to high risk of flooding, and this region is located in the urban area. Research Implications: There is a need for integrated management of water resources and urban planning, considering the socioeconomic and environmental vulnerability of flood-prone areas. Originality/Value: The study contributes to a better understanding of fluvial behavior in coastal watersheds impacted by unplanned occupations in their estuaries.