Estimating Embeddedness From Bankfull Shear Velocity In Gravel Streambeds To Assess Sediment Impacts On Aquatic Habitat and Biota

Excess fine sediment (<2 mm) deposition on gravel streambeds can degrade habitat quality for stream biota. Stream ecologists commonly measure fine sediment in streambeds via a metric called embeddedness, a measure of the extent to which coarse particles are surrounded by, or embedded into, a finer substrate. Embeddedness is physically measured to assess habitat quality and there are no widely used methods to estimate or predict embeddedness from remotely sensed data. Our preliminary results show that we can predict embeddedness in the Dan and Roanoke River Basins in Virginia and North Carolina from freely available, remotely sensed stream variables used to calculate bankfull shear velocity. We are conducting ongoing investigations on the relationship between bankfull shear velocity and embeddedness in gravel streambeds on a national scale through publicly available stream datasets that include embeddedness and other physical parameters. Additionally, we are exploring how embeddedness changes over time in response to changing hydrologic conditions and to what extent our predictive relationship holds. Our predictive relation for embeddedness can allow us to make predictions throughout an entire river network that will lead to more robust assessments of aquatic habitat and biota.