Statistical and Type II Error Assessment of a Runoff Predictive Model in Peninsula Malaysia

Flood related disasters continue to threaten mankind despite preventative efforts in technological advancement. Since 1954, the Soil Conservation Services (SCS) Curve Number (CN0.2) rainfall-runoff model has been widely used but reportedly produced inconsistent results field studies worldwide. As such, this article presents methodology reassess validity of and perform calibration with inferential statistics. A closed form equation was solved narrow previous research gap a derived 3D runoff difference for type II error assessment. Under study, SCS is statistically insignificant (alpha = 0.01) without calibration. CN0.2 72.58 Peninsula Malaysia 99% confidence interval range 67 76. Within these areas, underpredicts amounts when rainfall depth storm < 70 mm. Its overprediction tendency worsens cases involving larger events. For areas 1 km2, it underpredicted amount most (2.4 million liters) at 55 mm while nearly overpredicted by 25 liters reached 430 Malaysia. The must be validated datasets prior its adoption prediction any part world. practitioners are encouraged adopt general formulae from derive assessment models equations their studies.