ESTIMATIVA DOS PARÂMETROS DE EQUAÇÕES DE INTENSIDADE-DURAÇÃO-FREQUÊNCIA DE CHUVAS INTENSAS PARA O ESTADO DA BAHIA, BRASIL

Resumen

Understand the rainfall characteristics is important for urban and agricultural planning, as well as for engineering projects and works. The aims of this study was to determine the parameters of intensity duration and frequency equations (K, a, b, c) for 279 municipalities of the State of Bahia, Brazil, through 622 rainfall stations with data available from the National Water Agency of Brazil (ANA). Initially, a data series consistency study was carried out, followed by the breakdown of the maximum one-day rains into durations of 5; 10; 15; 20; 25; 30; 60; 360; 480; 600; 720 and 1,440 minutes and estimated maximum rainfall through probabilistic models for each duration and return period of 5; 10; 25; 50 and 100 years. Subsequently, the parameters (K, a, b, c) were adjusted using non-linear regression, with considerable R² values ​​above 0.96 for all study stations, considering one station per municipality. With representation of 67% of Bahia municipalities (279 municipalities), greater than the previous representation, only 4.5% of municipalities had adjusted equations (19 municipalities). Finally, the maximum precipitation intensities for the 10 and 50 year return periods and the duration of the 10 and 30 minute precipitation events were calculated and the spatialization of the information by geostatistical methods for the entire state with higher values ​​observed in the southeast coast. and south and lower intensities in the center of the state of Bahia.