Wet September start

Unsettled weather during the first half of September has raised the soil and groundwater levels. The hydrograph below shows repeated peaks, building in size up to a small peak flow event on 11 September (55mm precipitation over 10-11 Sep.).

Today's fieldwork included taking a velocity profile in the centre of the channel (see figure below), where the flow depth was 24cm. We could confirm that the mean flow velocity in the vertical profile occurs at the depth of 0.6 x depth (measured from the surface). The USGS wading rod that we use makes this assumption in setting the representative depth at which to take a single velocity measurement in each vertical profile.