New Rainfall Intensity-duration-frequency Curves for the Department of Montevideo, Uruguay

Abstract

The intensity-duration-frequency curves used in Uruguay are based, according to the author, in recording raingauges data recorded between 1906 and 1990. The availability of data from the last decades and the widespread perception that indicates an increasing trend in the frequency of heavy rainfall events recorded in these last decades, are the main reason to update the intensity-duration-frequency curves used in Uruguay. The update until 2005 of the curves for the Department of Montevideo had no generated significant differences. Extreme rainfall quantiles for all durations did not vary by more than 5 % from their corresponding values of the historic series. However, by analyzing only the 1981-2005 period, the curves showed a decrease between 10 and 20 % in peak intensity values of rainfall for average return periods, except for short duration events, from 1 hour to 20 minutes, where an increase of equal magnitude was found.