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A Fuzzy Set Theory Based Methodology For Analysis Of Uncertainties In Stage-Discharge Measurements And Rating Curve, Rajesh R. Shrestha, Slobodan P. Simonovic

Water Resources Research Report

River stage and discharge records are essential for hydrological and hydraulic analyses. While stage is measured directly, discharge value is calculated from measurements of flow velocity, depth and channel cross-section dimensions. The measurements are affected by random and systematic measurement errors and other inaccuracies, such as approximation of velocity distribution and channel geometry with a finite number of measurements. Such errors lead to the uncertainty in both, the stage and the discharge values, which propagates into the rating curve established from the measurements. The relationship between stage and discharge is not strictly single valued, but takes a looped form due …