Estimates of Shear Stress and Measurements of Water Levels in the Lower Fox River near Green Bay, Wisconsin

Turbulent shear stress in the boundary layer of a
natural river system largely controls the deposition and
resuspension of sediment, as well as the longevity and
effectiveness of granular-material caps used to cover and
isolate contaminated sediments. This report documents
measurements and calculations made in order to estimate
shear stress and shear velocity on the Lower Fox River,
Wisconsin.
Velocity profiles were generated using an acoustic
Doppler current profiler (ADCP) mounted on a moored
vessel. This method of data collection yielded 158 velocity
profiles on the Lower Fox River between June 2003 and
November 2004. Of these profiles, 109 were classified as
valid and were used to estimate the bottom shear stress
and velocity using log-profile and turbulent kinetic energy
methods. Estimated shear stress ranged from 0.09 to 10.8
dynes per centimeter squared. Estimated coefficients of
friction ranged from 0.001 to 0.025.