Developing rainfall intensity-duration-frequency curves for Dodola catchment to estimate peak discharge using frequency analysis

Abstract

The development of intensity-duration-frequency (IDF) curves is one of the most common and useful tools to estimate peak discharge. The purpose of this study was to develop the IDF curves for five selected stations in the Dodola catchment. The Ethiopian Road Authority (ERA) reduction empirical formula was used to estimate the short-duration rainfall intensity from daily rainfall data. The L-moment ratio diagram and three goodness-of-fit tests were used to identify the best-fit probability distribution. The IDF curves that were constructed using regionalised distribution were compared with at-site IDF curves. The difference between the two sets of IDF curves small differences, also, shows the same trend for all selected return periods. These IDF curves will help in the estimation of peak discharge in the catchment.