Estimativa das cotas de alerta de cheia: Bacia Apodi-Mossoró

Abstract

This study estimated flood alert levels for strategic points in the Apodi-Mossoró River basin, located in the Northeastern semi-arid region of Brazil, an area intrinsically vulnerable to extreme hydrological events due to rainfall irregularity. The methodology included a literature review, the localization and selection of fluviometric stations from the National Water Agency (ANA) and the Rio Grande do Norte Water Management Institute (IGARN) with consistent historical series, and the processing of annual maximum water level data to calculate frequency and recurrence rates using statistical methods. The results revealed that historical maximum water levels reached expressive values, such as 750 cm at the Pedra de Abelhas station (1944, Return Period (RP) = 64 years), 596 cm at Pau dos Ferros (1974, RP = 48 years), and 671 cm at Governador Dix-Sept Rosado (2008, RP = 40 years). It was observed that maximum water levels progressively increase from the upper to the lower course of the basin, with significant flood events occurring with relatively high frequency, indicating the region's high vulnerability to river floods. It was concluded that the precise calculation of alert levels is fundamental for improving monitoring systems and civil defense response capacity, mitigating the socioeconomic impacts of floods, and strengthening community resilience, especially in face of climate change projections.