Laboratory experiment dataturbidity response to increasing silt and clay concentration

These data were compiled during a laboratory experiment showing the turbidity response to increasing silt and clay concentration. The sediment used for the laboratory experiment was collected in the Grand Canyon study area, from the bank of the Little Colorado River, approximately 1 kilometer upstream from its confluence with the Colorado River. The sediment was passed through a 63 m sieve to isolate the silt-and-clay-size fraction. The silt and clay was completely dried in an oven (at 105 degrees Celsius for 12 hours), weighed, mechanically disaggregated, and added in stages to a measured volume of water to calculate concentration. The sediment was kept in suspension with an electric stirrer and turbidity was recorded after readings stabilized. The instrument used to measure turbidity was a YSI Incorporated Model 6136 probe, which is the same instrument used to collect turbidity in the study area. The purpose of collecting these data was to determine whether the turbidity response to very high suspended-sediment concentrations seen in the study area could be duplicated in the laboratory. It was expected and demonstrated in the laboratory that at very high suspended-sediment concentrations, as suspended-sediment concentration increased, turbidity values changed from a pegged or a constant value above the working range of the turbidity probe to lower values within the working range of the turbidity probe.

These data are associated with the technical note: Voichick, N., Topping, D. J., and Griffiths, R. E.: Technical note: False low turbidity readings from optical probes during high suspended-sediment concentrations, Hydrol. Earth Syst. Sci., 22, 1767-1773, https://doi.org/10.5194/hess-22-1767-2018, 2018.