RESERVOIR MANAGEMENT AND SEDIMENT BUDGET

摘要

The aim of this paper is to discuss reservoir management in the context of a catchment-wide sediment budget. This study has been performed in the Alpine Soelk-basin in Austria. Whereas at the moment reservoir management is mainly focusing on the structure itself herein the sediment budget of the whole catchment is included in the investigations. It is shown that there is a significant difference in the behavior and management of sediments depending on the size fraction. Coarse material - mainly bedload - shows a stochastic nature of erosion, transfer and deposition. In the Soelk reservoir bedload is deposited in the pre-sedimentation area at the upper end of the reservoir. Alternative measures like bypass systems are both technically and economically problematic for the given situation. The main emphasis of this paper lies on the fine material transport. Based on an intensive field monitoring program a numerical sediment transport model was calibrated and validated. Thereby areas with higher or lower erosion potential were identified. Data showed that especially larger events produce the high sediment input, which then cause intensive sedimentation within the reservoir. Using a numerical model the alternative of using density currents to avoid sedimentation in the reservoir was successfully tested.