Determination of Suitable Probability Distribution for Annual Mean and Peak Discharges Estimation (Case Study: Minab River- Barantin Gage, Iran)

Different methods are employed in applying probability distribution in hydrology. The most common among these methods is the Probability Distribution method. In this study in order to determine suitable probability distribution for estimating of annual discharge series with different return periods, annual mean and peak discharges over a 30 years’ time period had been collected from Minab river (Barantin gage) in Hormozgan province, Iran. After homogeneity and adequacy test, data has analyzed by SMADA software and residual sum of squares (R.S.S). The best probability distribution selected according to SMADA output and R.S.S results. Log Pearson type III with R.S.S (124.4) for annul peak discharge and Log Pearson type III and then Pearson with R.S.S (1.16) and (1.9) demonstrated the most fitting respectively, for annual mean discharge.