Generation of Rainfall Intensity Duration Frequency (IDF) Curves for Ungauged Sites in Arid Region

Abstract

We developed a method for Intensity Duration Frequency (IDF) curves in ungauged locations in arid region. The arid climate which covers most of Saudi Arabia is typically characterized by large temporal and spatial variations in rainfall distribution. The availability of long-term records of rainfall-runoff series would be useful to better estimate effective rainfall depth. The development process for an IDF curve for a remote, ungauged site is addressed through the use of rainfall record. The analyses focused on the application of two distributions: the Gumbel and Log Pearson III functions combined, to estimate the maximum rainfall for the various return periods in three stations in Al-Madinah region. The empirical intensity frequency equation is used to estimate rainfall intensity for design purposes for the ungauged location. The results of this research contribute to the development of IDF-based design criteria for water projects in ungauged sites located in arid and extreme arid regions.