Observations on flow hydraulics in a gauging station of a small stream with high suspended sediment load (Vallcebre, eastern Pyrenees)
Résumé
Water depth and sediment concentration have been measured with a good time resolution (every 2 min during flood events and every 20 min for the rest of the time) since 1994 at the gauging station of the Cal Rodó catchment (4.17 km2). Since October 2008, mean water velocity has been measured at the same resolution using an incoherent (or continuous) Doppler instrument mounted on the bottom of the gauging station. This study focuses on the impact of suspended sediment transport on water depth measurement and the effect of high loads of suspended sediment on flow hydraulics. We take into account the effect of suspended sediment concentration on the measurement of water depth by the hydrostatic pressure probe. We also examine the relationship between water depth and flow velocity and the effect of suspended sediment concentration on this relationship.