Transverse mixing in the Mobile River, Alabama

Transverse dispersion in the Mobile River was measured by (1) ground-based techniques using water samples and a fluorometer and (2) by aerial photography. Magnitude of the transverse mixing coefficient obtained by the two methods was 6.2 feet squared per second (0.58 metre squared per second) and 5.0 feet squared per second (0.46 metre squared per second), respectively. The value of the numerical coefficient k, which relates the transverse mixing coefficient E, to shear velocity U* and average depth of flow, d, by the relationship k=E_z/U*d, was 7.2.