Sediment Resuspension

Sediment resuspension is important because when sediments from the lake bottom are resuspended, they can be eroded or transported.  This can result in deposition of sediments and the resuspension into the water column of hazardous particles that had settled out. 

To estimate the potential of boat waves to resuspend sediments when compared to wind waves, I calculated the bottom velocity produced by various wave heights.  From the CEE 514 lecture notes, the equation for bottom velocity, in its simplified form, is:

U_b = π*H/(T*sinh(kd))          where k = 2π/L

Shown in the graph below is the bottom velocity generated by waves created by both wind and boats.  The boat waves are from a distance of x=30.48 m from the shore (the edge of the no-wake zone).

Wave Height           Wave Power           Sediment Resuspension