HYDRAULIC UNCERTAINTY IN RISK ANALYSIS.

Considerable effort has been expended in defining and evaluating hydrologic uncertainties; however, the analysis and evaluation of hydraulic uncertainties has received little attention. The hydraulic uncertainty originates mainly from the inability of a mathematical model or an empirical formula to completely describe the real physical flow process. Risk and reliability models have been developed that combine both the hydrologic and hydraulic uncertainties to define an overall risk. First, the effect that hydraulic uncertainty has on the overall risk evaluation for hydraulic structures and second, new methods to evaluate hydraulic uncertainty are explored. The results of this investigation show that only a few variables dominate the variation in the hydraulic uncertainty, which makes the analysis for hydraulic uncertainty easier than might be expected.