Runoff and erosion plots, Pradel
Résumé
Runoff was collected in the bottom part of the hillslope. The water depth was measured every minute with a 1 mm resolution using a limnimeter (OTT Thalimede) within a H-flume designed following the US Soil Conservation Service recommendations. The stage-discharge rating curve was built experimentally and allowed to calculate discharge with a median relative uncertainty of 10%. A sequential sampler containing 24 bottles of 1 l capacity sampled water and eroded particles within the H-flume. When critical thresholds of water depth or water depth variation were exceeded, the data logger triggered the sampling of water and eroded particles. Thus, the time intervals between each two samples were irregular, depending on the shape of the hydrograph. The suspended sediment concentrations were estimated by weighting the water samples after drying them during 24 h at 105 °C with a median relative uncertainty of 15%.