Séminaire Liquides/Mat. molle

Vendredi 16 Mai 2014 à 11h00.

Mathematical models of mass transfer across the sediment-water interface in turbulent streams

''The hyporheic zone is the porous sediment beneath and adjacent to a river where surface water and groundwater mix. Its physical and chemical environment supports a community of organisms that can collectively function as a “river’s liver”—removing contaminants and cycling carbon, energy, and nutrients. The hyporheic zone also regulates stream temperature and sediment budgets, serves as a fish spawning ground and refuge for, and provides a rooting zone for aquatic plants. These ecosystem services require vigorous exchange of water, nutrients and energy across the sediment-stream boundary, a process referred to as hyporheic exchange. There has been considerable multi-disciplinary research focus on the biogeochemistry of the hyporheic zone in recent years. However, more research is needed to understand and model the critical interfacial mass transfer mechanisms and residence times within porous sediments. This presentation will discuss: the current understanding of these mechanisms; recent progress by the speaker and his colleagues at The University of Melbourne; and future challenges.''