Author(s): S. A. Kantoush; T. Sumi

Linked Author(s): Sameh A. Kantoush

Keywords: Sediment management techniques; Sediment excavation; Reservoir sedimentation; Sediment replenishment; River morphology

Abstract: In Japan an effective means for reservoir sediment management is to excavate the accumulated sediment and replenishing the downstream reaches of the dam. In an effort to restore the lower reach of the river to a more natural ecosystem an artificial flood release was designed to flush the replenished sediment at the banks of Uda River downstream of Murou dam. In order to evaluate the effect of the sediment replenishment on the river morphology, LSPIV and IC-Tag technology are undertaken to monitor surface velocity and gravel movements on the river bed. Since 2006, six attempts of sediment replenishment for rebuilding vital sediment sand bars below Murou dam are in progressing. Pre-and post-sediment replenishing measurements clarified the effect of the new improvement in riverbed formation. The results indicate that the replenished sediment volumes and flushing discharges were not sufficient to enhance the downstream bed morphology and the biodiversity of Uda River. Moreover, the interval between flushing flows should be reduced when higher sediment volumes are supplied.

DOI:

Year: 2011