Redução do risco de desastres hidrológicos: aperfeiçoamento do sistema de alerta na bacia do rio Capivari, RJ

Abstract

Current disaster risk reduction policies seek to prevent new threats, reduce existing ones, and increase resilience. The lack of continuity in data collection and the lack of professionals with specific knowledge in the civil defense agencies evidences the need for disaster risk reduction methodologies. The geomorphological characteristics favorable to the occurrence of abrupt flooding in the Capivari river basin, especially after the January 2013 event in Xerém, Duque de Caxias, RJ, encouraged the present research to propose improvements in the current flood warning system, with the establishment of rainfall thresholds from hydrological monitoring data. The work methodology consists of analyzing the correlation between rainfall, river level and the participation of civil society in the identification of occurrences with the civil defense in order to allow the creation of a database of hydrological disasters and subsequent design of the lines critical for changes in monitoring stages. The mapping of areas susceptible to flooding, alert emission thresholds, and curve utilization as compiled data analysis tools of hydrometeorological monitoring were able to assess the risks of disasters and the anticipation of possible damages. Technical assessments such as frequency analyzes of extreme events; hydraulic modeling; correlation between rainfall and flood, and the definition of operational states and monitoring stages for the prevention of disasters in the Capivari river basin were defined as primary actions for the improvement of flood warning system and incorporation in civil defense actions. In view of a critical political and economic scenario and a setback for disaster prediction, it is understood that there is a need for simple tools to support decision-making for civil defense agencies. Although the proposal of this work does not replace the technical agent of the monitoring in real time, these tools imply in greater comprehensiveness and assertiveness of the competent bodies for emission of flood warning.