Assessment of the hydromorphological effectiveness of sediment augmentation measures downstream of dams

This article presents assessment methods for the hydromorphological effectiveness of sediment augmentation measures downstream of dams. First, we describe different ways of quantifying hydromorphological effectiveness based on typical objectives of sediment augmentation. Then we show how field observations and physical and numerical modelling can be combined to investigate the influence of design criteria and site conditions on hydromorphological evolution following sediment augmentation. We provide examples of the influence of geomorphic units on bedload transport patterns and the influence of augmentation repetition frequency on hydromorphological variability. The results show that geomorphic units can influence deposition patterns and that consecutive sediment augmentation increases morphological and hydromorphological variability. Finally, we discuss the results and summarize some practical implications.