Influência de eventos de precipitação pluviométrica sobre a gestão de recursos hídricos na Região do Alto Curso da Bacia Hidrográfica do Rio Paraíba.

Abstract

Water resources are essential for human survival and socioeconomic development. The occurrence of intense rainfall and prolonged droughts impacts the availability and distribution of water, affecting water storage and supply systems. This study aimed to investigate the influence of extreme rainfall events on water resource management in the upper zone of the Paraíba River basin, located in the Brazilian semi-arid region. The methodology used was based on the analysis of historical rainfall series and the volume stored in the Epitácio Pessoa reservoir, from 1985 to 2023, using data provided by the Executive Agency for Water Management of the State of Paraíba (AESA) and the Climate Prediction Center (CPC). Statistical techniques and the calculation of the rainfall anomaly index (RAI) were applied to categorize the years as dry, normal, and wet. It was possible to identify high interannual variability in rainfall in the region, with frequent occurrences of severe drought events. Periods of severe drought compromised the storage levels of the region's main reservoirs, including the Epitácio Pessoa dam, which reached 5% of its total volumetric capacity in December 2016, reaching the dead volume or technical reserve (52,613,507m³). Years considered rainy or humid resulted in high runoff, soil erosion, and total or partial recharge of surface and groundwater aquifers. The application of the IAC (Integrated Climate Assessment) demonstrated that 30% of the years analyzed presented extreme conditions, with a direct impact on water resource management and the water security of the population supplied by the Epitácio Pessoa reservoir. There is a need to expand climate monitoring and predictive modeling to anticipate future extreme scenarios that aid in the development of sustainable solutions. There is a need to strengthen governance mechanisms and adaptive management in the face of climate change, through the integration of climate forecasting systems with structural measures, using water and soil conservation techniques that can reduce the impacts of rainfall variability, ensuring the continuity of hydroclimatological monitoring, rainwater harvesting, adoption of sustainable agricultural practices such as the use of efficient irrigation systems, and the reuse of treated and untreated wastewater with specialized technical support. It is expected that the results presented will support strategic decisions aimed at strengthening governance and adaptive management of water resources in the upper reaches of the Paraíba River basin. The adoption of preventive and adaptive measures is essential to minimize the impacts of climate variations and ensure water security for the population supplied by aquifers and water sources. Keywords: Extreme events, Water resources, Water security