Suspended sediment transport modelling and integrative research during maintenance work at the Gepatsch reservoir - investigation of benthic invertebrates
Abstract
The sedimentation and the sediment management of hydropower reservoirs is one of the big global issues concerning future hydropower use. Exemplarily for Asia a reduction of 80 % of the potential storage volume is predicted by 2035. For Europe those thresholds in sedimentation are predicted by 2080. Consequences of those sedimentations are beside a reduction of the storage volume and the related restriction in hydropower production, effects on downstream aquatic ecology related to artificial downstream flushing of deposited fines. Impacts on aquatic ecology, however, are manifold. Consequences might be given due to changes in morphology and sediment quality with possible clogging of the gravel matrix and an increase of stress due to an increased turbidity. The presented case study is dealing with a lowering of the water surface level of the reservoir Gepatsch (Tyrol) beyond the operational level. Thus, an increased erosion of fines might be expected. Based on the awareness of possible negative ecological consequences a complex set of measures and an integrative monitoring design has been developed. Monitoring is based on detailed event based sampling of the reservoir by drones for quantification of eroded sediments. Moreover, high resolution turbidity data are available for the entire Inn river based on nine monitoring stations. In addition freeze-core samples are taken before and after the lowering of the reservoir volume, in combination with cocooning of brown trout during the spawning period. In this part of the reaseach work, benthic invertebrates are monitored as biological qualtiy element. Based on the detailed monitoring recommendation for future sediment management for alpine reservoirs will be achieved.
keywords suspended sediment benthic invertebrates clogging
Publikationen
Project staff
Wolfram Graf
Assoc. Prof. Dr. Wolfram Graf
wolfram.graf@boku.ac.at
Tel: +43 1 47654-81221
Project Leader
01.09.2015 - 01.04.2017
Florian Dossi
Dipl.-Ing. Dr. Florian Dossi
Tel: +43 1 47654-81211
Project Staff
01.09.2015 - 01.04.2017
Patrick Leitner
Dipl.-Ing. Dr.nat.techn. Patrick Leitner
patrick.leitner@boku.ac.at
Tel: +43 1 47654-81243
Project Staff
01.09.2015 - 01.04.2017