Análise dos extremos de vazão no Rio Mundaú e sistemas sinóticos associados no período de 1990 a 2019

Abstract

This study aimed to analyze extreme flow events in the Mundaú River and identify the synoptic scale systems that directly influenced these cases, between the years 1990 to 2019. For this analysis, daily flow data from the Agência Nacional de Águas (ANA) for four fluviometric stations located in the cities of Murici; Rio Largo; Santana do Mundaú and União dos Palmares, and with these data the percentile technique was applied, and then a value equal to or greater than the 95th percentile was considered an extreme flow event. With these values, 19 cases were identified where the flow was considered extreme in at least one fluviometric station. Soon after, the systems that acted in the region of the River Mundaú Watershed (RMW) were identified, through the data of the ECMWF model in 10 levels of the atmosphere and satellite images. The year 2000 was the year with the highest number of occurrences of extreme flow (03), which represents 16% of the total. Dividing the three decades, from 1990 to 1999 it concentrated 31.5% of the events, from 2000 to 2009, 52.5%, and from 2010 to 2019, 16%. Extreme flow events in the Mundaú River had a concentrated distribution between the months of autumn and winter, with the months of June (9) and August (4) showing the highest number of cases within the series. As for the systems that were identified, 15 cases with Wave Disturbance of Trades Winds(WDTW); 2 with Upper Tropospheric Cyclonic Vortices (UTCV) and 2 with Tropical Waves (TW).