Author(s): El Mehdi Chagdali; Cédric GOEURY; Benjamin DEWALS; Sébastien ERPICUM; Matthieu SECHER; Rem-Sophia Mouradi; Kamal EL KADI ABDEREZZAK

Linked Author(s): EL MEHDI CHAGDALI, Cedric GOEURY, Sébastien Erpicum

Keywords: Flow pattern; Shallow reservoirs; Reservoir sedimentation; Numerical modelling; Sediment transport

Abstract: Shallow reservoirs are hydraulic structures used for stormwater management or for trapping sediments. Sedimentation in these structures must be minimized or maximized. Sedimentation depends on the flow structures, which in turn depend on the reservoir geometrical shape and its hydro-sedimentary characteristics. In this work, the ability of two-dimensional (2D) depth averaged numerical models using Shallow-Water Equations to simulate flow and sedimentation in shallow reservoirs is examined. Existing laboratory rectangular reservoirs with different locations of inlet and outlet channels and bottom topography (i.e. flat bottom, sediment deposits), are simulated. The model is applied on real shallow basin which operates as a lower basin of a Pumped Storage Hydropower Station. For laboratory cases, a detailed study of the effects of various user-defined numerical model parameters is performed, including the numerical scheme for solving the advection step for velocity and turbulence and the turbulence model. Satisfactory model-data agreements are obtained with TELEMAC-2D using the Spalart-Allmaras turbulence model. Simulating the field case, the hydro-sedimentary numerical model TELEMAC-2D coupled with GAIA has been used to explore potential enhancements for the management and maintenance of the basin. A scenario with a deflector placed at the entrance has shown its efficiency in increasing sediment deposits in the northern part of the reservoir where dredging operations can be conducted easily.

DOI: https://doi.org/10.3850/IAHR-39WC252171192022SS506

Year: 2022