Role of rainfall characteristics on runoff prediction accuracy of SCS model

Many different runoff prediction methods are being used among which SCS model hasbeen applied throughout the globe. It is therefore very important to evaluate thecircumstances and input specifications under which such models could be applied. Thepresent study was conducted to investigate the role of rainfall main characteristics onaccuracy of SCS model in runoff prediction for Kasilian and Darjazin watersheds. Forthis purpose, the simultaneous rainfall-runoff data were selected and the storm runoffwas estimated using determining rainfall characteristic, providing Curve Number mapand calibrating the model. In order to determine the effects of rainfall characteristics onmodel output, the standardized values of regression coefficient (β) of the best fittedmultiple regression, developed between rainfall circumstances and maximum storageindex coefficient, were determined. The results of the study showed the depth,maximum rainfall in concentration time, maximum 30 minutes intensity, 2nd quartileand 1st quartile have the highest rate of effectiveness on model output respectively.