Flood risk assessment method in urban areas of Rio Grande do Norte

Abstract

Brazilian urbanization occurred in a different way, in this perspective the most attractive places were being occupied by the real estate market, while the population with lower purchasing power was forced to occupy marginal areas of the cities, because they were economically attractive, but quite dangerous. In the state of Rio Grande do Norte, floods are the second largest type of recurrent disaster. From 2003 to 2023 this type of occurrence reached 8%, second only to droughts that added up to 92%, in view of this, we are faced with the following problem: what is the behavior of the floods of the Piranhas-Açu River? What is the degree of flood risk in the urban areas of Alto do Rodrigues, Pendências and Carnaubais? We used the methodology developed by Ferreira (2019). That emergency flood maps were used combining with the vulnerability index to define a final risk map. Three years (1988; 2005 and 1985) were selected for the construction of the emergency flood maps. In the results, the risk maps showed differentiated gradations, which extend between the smaller and the larger bed, this factor demonstrated that the municipalities exert a certain pressure on the environmental elements, such as the rivers, both in Carnaubais and Pendências the risk zone is very close to the urban fabric of the city, in the case of Alto do Rodrigues the risk area is projected within the urban fabric of the city,  all this demonstrates how vulnerable the municipalities and their inhabitants can be, in a country of continental dimensions like Brazil.