Calibration approaches for hydraulic river models for high and low flows: A review

Global climate change affects all aspects of river processes. It is expected that discharge extremes will occur more often in the future and that the probability of high and low flows in a shorter period will increase. Given these changes in hydrometeorological conditions, the question arises whether it is possible to set up a hydraulic model that simulates both high, intermediate and low flows in rivers accurately. However, hydraulic models are currently calibrated for a specific discharge range. Consequently, it is not possible to evaluate the effects of river interventions for a wide range of conditions with such a calibrated model. Therefore, this study gives an overview of the current state of hydraulic calibration approaches applied in literature and aims to give insights in how these calibration approaches can be improved such that a hydraulic model can be calibrated and applied for varying discharge conditions. Exploring the literature showed that the most commonly used parameter for calibration is roughness that is calibrated one time for one specific discharge or calibrated separately for different calibrated ranges.