IAHR Document Library

« Back to Library Homepage « Proceedings of the 36th IAHR World Congress (Hague, 2015)

Backwater Rise Due to Driftwood Accumulations

Author(s): Lukas Schmocker; Dieter Brändli; Volker Weitbrecht; Robert M. Boes

Linked Author(s): Robert Boes, Volker Weitbrecht

Keywords: Backwater rise; Bridge clogging; Driftwood retention; Flooding; Large woody debris

Abstract: During flood events mountain torrents and rivers may transport significant amounts of driftwood or large woody debris (LWD) .This driftwood can accumulate and block spillways at hydropower plants as well as bridges and weirs along rivers. Blocking of a river cross section will always lead to a backwater rise and possible overtopping of the flood embankment. Furthermore, also manmade driftwood retention structures such as debris racks result in a backwater rise, once they start to retain driftwood. For both cases, it is of primary importance to quantify the resulting backwater rise. The present paper summarizes a series of laboratory tests, where the backwater rise due to a driftwood accumulation at a rack or bridge was investigated. The backwater rise was determined depending on various flow conditions and for different driftwood characteristics. The results highlight the decisive effect of the Froude number and the porosity of the driftwood accumulation on the backwater rise.


Year: 2015

Copyright © 2024 International Association for Hydro-Environment Engineering and Research. All rights reserved. | Terms and Conditions