Author(s): Muto Yasunori; Kanda Keiichi; Zhang Hao; Nakagawa Hajime
Linked Author(s): Keiichi Kanda
Keywords: Falling works; Weir removal; Bed degradation; Sand bar; Experiment
Abstract: There often exists a conflict between flood alleviation and environmental preservation in river management. One of the problems is how to design and construct the river-crossing structures such as falling works. Some attempts in order to restore and/or compensate river consecutiveness divorced by the structure have been adopted, however its effect on river bed morphology is not well explored yet. Following to the preceding paper (Muto et al., 2008), further laboratory experiments were conducted to study effects of falling works improvement on degradation and instability of the upstream bed. In this paper the effect of discharge variations on the upstream bed response is examined. Three discharge conditions are selected, assuming small, annual maximum and plan flood levels respectively. In addition the shape of removed part is varied systematically and how a sand bar and a thalweg are affected is explored.
Year: 2009