Author(s): L. Cassan; L. Guiot; G. Belaud

Linked Author(s): Gilles Belaud

Keywords: Tide Gate model; Tide gate management; Gate design; Fish passage; Water quality

Abstract: Tidal gates are hydraulic structures that prevent salt water from entering in freshwater marshes. However, they also block fish migration. For a side hinged gate, the migration can be facilitated by maintaining a little opening during all the tide. In this paper, the discharge coefficient of such a gate is evaluated based on numerical and experimental studies. It is found that the experimental discharge coefficients evolve with the difference between upstream and downstream water depths. Using shallow water simulations to estimate energy loss, we derived a model able to predict discharge with reasonable accuracy. An output of the model is the design of a stiffener device that limits salt water intrusion at high tide. Resolving the angular momentum, the optimal stiffener stiffness can be found to maintain opening sufficient for migration, while reducing greatly the volume of salt water intrusion in comparison with a constant block.

DOI: https://doi.org/10.15142/T3BW72

Year: 2018