Estimating the Intensity Equations for Rain Intensity Frequency Curves (Mosul /Iraq)

The relationship between the rainfall intensity, duration, and frequency (IDF) is widely used in water resources engineering designing hydraulic structures, such as culverts sewage systems, for reducing controlling floods. In this study, curves of were found five rain stations registered different regions northern Iraq, i.e., Mosul, Tal-Afar, Sinjar, Rabia, Tal-Abta, periods extending from 1990 to 2019. Indian Meteorological Department (IMD) empirical equation was utilized obtain data during short periods, 10, 20, 30, 60, 120, 180, 360, 720, 1440 minutes. Also, three probability distributions used: Gumble Distribution, Log Pearson Type III Log-Normal various return (2, 5, 25, 50, 100) years. Easy fit 5.6 software includes tests (Kolmogorov-Smirnov, Anderson -Darling (AD), Chi-Squared (χ2)) determine most suitable distribution observed among distributions. results demonstrated an insignificant difference applied statistics values that fell within significance level, with priority Pearson-III distribution.