Examining Uncertainties in Intensity-Duration-Frequency Curves for Babylon City – A Comprehensive Analysis

Abstract

Rains are one of the complementary components of the hydrological cycle, so engineers must be able to determine as much as possible in order to design facilities dealing with the assembly, transportation and storage of rains.. The objective of this research is to comprehensive analysis the data of the depth of annual rainfall (mm) of the Babylon Station for the purpose of finding the characteristics of the distributions of observed frequency. In this paper data of annual rainfall depth (mm) by taking maximum value from one year’s data as well as the rate of data values for one year from 1991 to 2021 for one stock station in Iraq, Babylon for the purpose of creating the characteristics of the distribution of observed frequency. An attempt was made to fit three of the available theoretical distributions, the Normal, Log Normal and Gamma distributions. The Chi-Square, Kolmogorov-Smirnov and Anderson-Darling indices examined for the purpose of comparing theoretical distributions with viewed distributions. Gumbel’s extreme value distribution, the Normal and the Log Normal distribution were used to know the suitability of the data and for the periods of 5, 10, 15 and 50 years. In the remainder of this research, grants of intensity-duration-frequency (IDF) curves of the rainfall were obtained and repeated for the rainfall of the Babylon observation station for 15, 30 and 60 minutes.