Recorded rainfalls in the period from 1981 to 2004 at the meteorological station of Urussanga, SC (Latitude 28° 31' S, longitude 49° 19' W, altitude 49 m), were analyzed. From the series of annual maximum precipitation, the maximum rainfalls were estimated using the Gumbel-Chow distribution, with durations varying from 5 min to 24 h and also for the duration of one day, considering the return periods of 2, 5, 10, 20, 25, 50 and 100 years. The adherence of the data to the Gumbel-Chow model was proven through the Kolmogorov-Smirnov test with a significance level of 5%. The ratio between the 24 h maximum precipitation and the maximum precipitation of one day varied from 1.17 to 2 years return period up to 1.11 for the 100 years return period, with average of 1.13. The coefficients of the equation proposed by Bell were adjusted to estimate the relationship between the rain with duration of t min and return period T years as a function of the maximum rain with a return period of 10 years and duration of 1 h. In the same way, the coefficients of the Bell equation were adjusted based on the maximum rain with return period of 10 years and duration of 1 day.
heavy rainfall; hydrology; drainage
