Nonstationary intesity-duration-frequency curves for medellin river basin

Abstract

The current Intensity-Duration-Frequency (IDF) curves assume that the precipitation does not vary significantly in time, what induces to underestimate the extreme events and at the same time increases the risk of flooding and damage to the infrastructure. As a consequence, methodologies that allow the estimation of climate change condition should be studied, taking into account a non- stationary approach as the one used in this study, in which stationary and non-stationary IDF curves were estimated for 9 pluviographic stations located in the Medellin river basin. To adjust the precipitation time series, the distribution of extreme values EV1 was used; its stationary parameters were calculated by means of the L-moments method and the non-stationary ones by the mobile windows. The effect of climate change on high intensities and small durations have been evidenced, obtaining that the stationary approach can underestimate extreme events up to 39%.