IAHR, founded in 1935, is a worldwide independent member-based organisation of engineers and water specialists working in fields related to the hydro-environmental sciences and their practical application. Activities range from river and maritime hydraulics to water resources development and eco-hydraulics, through to ice engineering, hydroinformatics, and hydraulic machinery.
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You are here : eLibrary : IAHR World Congress Proceedings : 34th Congress - Brisbane (2011) : THEME 5: Environmental Hydraulics and Hydrology : Effect of hyporheic flows induced by alternate bars on benthic oxygen uptake
Effect of hyporheic flows induced by alternate bars on benthic oxygen uptake
Author : D. Tonina1, A. Marzadri2 and A. Bellin2
Hyporheic flows stem primarily from near-bed pressure gradients induced by the interaction between stream flow and topography. They mix in-stream and pore waters through a pumping mechanism, which drives surface water (downwelling flux) in the streambed sediment in high-pressure zones and subsurface water (upwelling flux) into the stream in low-pressure zones. Downwellingf fluxes carry river biological oxygen demand (BOD), dissolved oxygen (DO) and ammonium (N) into the sediment where biochemical reactions (respiration and nitrification) consume DO. Here, we present an analytical model for quantifying the benthic oxygen uptake rate (BUR) in gravel bed rivers with alternate-bar morphology and we show the relationship among stream morphodynamic parameters and solute (BOD, DO and N) concentrations on BUR. Our model analytically solves the hyporheic flow field and the solute transport equations with advection, longitudinal diffusion and reactions modeled as first order kinetics in a Lagrangian framework.
File Size : 369,935 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 34th Congress - Brisbane (2011)
Article : THEME 5: Environmental Hydraulics and Hydrology
Date Published : 01/07/2011
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