Author(s): Sudesh Dahal; Frederic Martin Evers; Robert Michael Boes And David Florian Vetsch
Linked Author(s): Frederic Martin Evers, David Vetsch
Keywords: Reservoir Sedimentation Numerical Modelling Storage Hydropower
Abstract: Reservoir sedimentation has a negative impact on dam-reservoir systems causing progressive reduction of the storage volume and impaired functionality of dam safety outlets. The global situation is alarming because the rate of loss of storage capacity is not balanced by the construction of new dams. With increasing water/energy demand amidst climate change impacts, the sedimentation issue is more amplified and management actions need to be prioritized to ensure sustainable storage. An in-depth investigation of governing processes is fundamental to plan for management strategies. In this study, the sedimentation dynamics in the seasonal storage reservoir Gigerwald in the Swiss Alps is investigated using 1D numerical modelling. The associated modelling challenges related to hydraulic jump and strongly varying geometry at the inflow section are identified and overcome by a careful model setup and selection of numerical parameters. Two distinct periods of sedimentation are referred to for model calibration and validation. A set of modelling parameters is obtained that produces a good agreement between modelled and monitored sedimentation processes. The validated model provides a basis for further investigation of management strategies along with climate change impacts.
Year: 2025