Breach of Duty (Not): Evaluating the Uncertainty of Dam-Breach Flood Predictions

摘要

Dam-breach flood analyses rarely take into account the uncertain nature of numerical model parameters when assessing the flood hazards of potential failures. Solution uncertainty is evaluated here using a point-estimate method that provides a direct and efficient computational procedure to obtain moment estimates (specifically, the means and variances) of calculated peak water-surface elevations, peak discharges, and flood peak travel times. The method is applied to Big Bay Dam to define bounds on downstream flood hazards having specified pexceedance probabilities. Comparison to peak water-surface elevations that were produced by actual failure of the dam shows the approach to provide a reasonable estimate of downstream flood hazard uncertainty.