Portable Device for Measuring Sediment Resuspension

摘要

A portable device for measuring sediment resuspension has been developed. The device consists of a cylindrical chamber inside of which a horizontal grid oscillates vertically. The sediments whose properties are to be determined are placed at the bottom of the chamber with water overlying them. The grid oscillates in the water and creates turbulence which penetrates down to the sediment-water interface and causes resuspension. The amount of material resuspended is proportional to the frequency of the grid oscillation. The device has been calibrated by comparing the concentrations of the resuspended sediment at different grid frequencies with the concentrations in an annular flume where the bottom shear stress is known. The device can be used in the laboratory for rapid and reasonably accurate measurements of resuspension. The device has also been tested on board ship and can be used in the field for rapid surveys of resuspension of undisturbed sediments.