STORM RESAMPLING FOR UNCERTAINTY ANALYSIS OF A MULTIPLE-STORM UNIT-HYDROGRAPH

Due to various types of uncertainties involved in the estimation of a unit hydrograph (UH), the UH derived by any method is subject to uncer tainties. Based on the concept of the bootstrap resampling technique, a practical methodology called storm resampling is proposed to quantif y the uncertainties of multiple-storm UH ordinates and any parameters involved in the estimation of the multiple-storm UH. The important UH ordinates and parameters may include UH peak discharge, UH time-to-pea k, UH volume, condition number related to the effective rainfall matri x, mean square error of the UH, and ridge parameter. The proposed boot strap-based storm resampling technique, along with the least squares a nd ridge least squares solution techniques, is applied to typhoon stor m events over a watershed in Taiwan. The methodology can be applied to other UH solution techniques and other hydrological and hydraulic sim ulation/optimization models. (C) 1997 Elsevier Science B.V.