Author(s): Hang Wang, Hubert Chanson

Linked Author(s): Hubert Chanson

Keywords: Standard box culverts, fish passage, fish-turbulence interactions, dimensional considerations, energy consumption

Abstract: Waterway culverts are very common hydraulic structures along streams and water systems, in rural and urban drainage networks. Current expertise in environmental hydraulics of culverts is limited, sometimes leading to inadequate fish passage with adverse impact on the catchment eco-system. Recent recognition of the ecological impact of culverts on natural streams led to changes in culvert design guidelines. It is believed that fish-turbulence interplay may facilitate upstream migration, albeit an optimum design must be based upon a proper characterisation of both hydrodynamics and fish kinematics. Basic dimensional considerations highlight a number of key parameters relevant to upstream fish passage, including the ratio of fish speed fluctuations to fluid velocity fluctuations, the ratio of fish response time to turbulent time scales, the ratios of fish dimension to turbulent length scale, and the fish species. Combining the equation of conservation of momentum applied to an individual fish, the instantaneous thrust and power expended during fish swimming may be derived from fish kinematic data, including the associated energy consumption. Within basic assumptions, the present findings suggest that the culvert invert slope may affect significantly the energy spent by the fish to provide thrust during upstream culvert passage

DOI:

Year: 2017