Quantifying Diyala River basin rainfall-runoff models for normal and extreme weather events

Abstract A variety of methods, including both modeling and non-modeling water balance techniques, are used in this study to estimate availability allocated for different demands. The area under investigation is the shared Diyala River basin between Iraq Iran, which vulnerable climate change impact upstream control aims enhance watershed management. Two rainfall-runoff models were applied, Tanh curve model modified runoff simulation at Derbendkhan Hemmrin hydrometric stations. Data from two meteorological stations (Khanakin Sulymania) one Iran (Sanandaj) 20 hydrological years (2000–2020) was used. Some goodness fit indicators evaluate reliability outcomes, correlation coefficient, root mean squared error, absolute deviation volume, index agreement. Statistical analysis shows no statistically significant difference observed predicted all winter, spring, annual time scales when using model, or monthly extreme wet events method. more accurate than applied only Sulymania Sanandaj stations, as it required a considerable amount precipitation least semi-humid areas.