Integration of morphometric attributes and the HAND model for the identification of Flood-Prone Area

Climate change projections indicate an increase in intense rainfall events with consequent river flooding, which could lead to devastating natural disasters with serious consequences for the quality of life of populations. The main objective of this work was to determine and analyze the flooding potential of watersheds by integrating morphometric attributes and the HAND (Height Above Nearest Drainage) model. The study focused on the Bocaina Stream Basin (BSB), located in the State of Minas Gerais in southeastern Brazil. The BSB fully covers the urban area of the city of Passos, which has long suffered from flooding. In this work, the following cartographic products were generated at a scale of 1:50,000: a map of the morphometric susceptibility to flooding, which classifies the subbasins of the BSB based on five morphometric parameters; a map of the height above the nearest drainage, which was obtained via the HAND model; and map of the topographic predisposition to flooding, which was obtained through the integration of the morphometric flood susceptibility information and the HAND model information. Based on the map of the topographic predisposition to flooding, the BSB area shows the following classes of flood susceptibility: 75%—very low, 11%—low, 9%—medium, and 6%—high. Although the high and medium classes represent the lowest percentages in terms of basin area, they are predominantly located in areas near the drainage channels. When these areas are occupied, as is the case in the city of Passos, flooding can have considerable impacts.