Estimation of local hydrodynamic conditions in headwater catchments : implications for the conveyance of suspended particles

Laboratoire de rattachement : LTHE

Encadrant : Nicolas GRATIOT, Cédric LEGOUT, participants V.Wendling, H.Michallet (LEGI)

Téléphone : 04.76.63.55.39

Mots clés : Cours d’eau de montagne, Sols et Sédiments, Paramétrisation hydro-sédimentaire.

Contexte et objectifs de la mission de stage :

During their transport from the mountains to the oceans, sediments undergo a number of mechanical and physicochemical alterations that can dramatically change their conveyance downstream. Laboratory experiments were performed (at LEGI and LTHE laboratory)to characterize the morphometric properties (size, density, settling velocity) of freshly eroded aggregates and of estuarine flocs. Under similar hydrodynamic forcings, aggregates behave inert while estuarine flocs have a high ability to flocculate.

The training period aims at identifying precisely the hydrodynamic conditions (sediment concentration and turbulence levels) that may be encountered at in headwater catchmentsin order to criticize the representativeness of laboratory experiments conducted previously. The study will be based on a literature survey, measures of hydrodynamic conditions with a micro acoustic velocimeter and analysis of laboratory and field datasets.

The project will be conducted in close relation with two international partners in the UK (A.Manning, University of Plymouth) and Canada (I.Droppo, Environmental Canada).