Investigation of the propagation of multi-inflow turbid density currents in a deep narrow reservoir using three-dimensional modeling : Maroon Reservoir , Iran

In reservoirs with narrow morphologies, a dense tur bidity current, originated from a riverine flood, m oves downstream along the thalweg and its influence of the euphotic zone depends on mixing behaviors near the plunge point. However where lowto-moderate density currents form overflows or inte rflows, the euphotic zone through a reservoir can b e affected with increasing turbidity, which alters light penetratio n, the thermal evolution of stratification, and hen c the overall aquatic ecosystem. Numerical modeling of the reservoir hydr odynamics with density currents can provide insight into fate of different types of turbid inflows and help develop proper reservoir management strategies. In this study a three-dimensional (3D) numeric al hydrodynamic model coupled with a particle dynam ics model has been used to simulate turbid density currents developed from multiple stream inflows in a large stratified reservoir. The Maroon reservoir, in southwest Iran, has a deep and narrow m rphology formed by the connection of two main im poundments and a narrow canyon. Turbid inflows with multiple suspend d sediment sizes, determined by means of a grain-s ize analysis of the river-suspended sediments, have been simulated. Mod el f rcing conditions for the main stem Maroon rive were developed from available measured flows and sediment, whereas inflows and sediment for two minor streams were ca lcul ted by using a rainfall-runoff model and site-specific flow-sedi ments relationships. The numerical model shows illu trates different fates and turbidity effects of different sediment size cl asses. © 2015 The Authors. Published by Elsevier B.V. Peer-review under responsibility of organizing comm ittee of ICWRCOE 2015. * Corresponding author. Tel.: +49-561-804-3262; fax : +49-561-804-3953. E-mail address: behnam.zamani@student.uni-kassel.de 2 Author name / Aquatic Procedia 00 (2015) 000–000