Field Measurement of Turbidity Maximum in Hiji River Estuary

摘要

The volume concentration of suspended solid in estuary increases rapidly in the phase in which the direction of longitudinal flow velocity reverses, and it takes an almost uniform value in the phase in which the downstream flow velocity is maximal. The increase of volume concentration is caused by the transportation of suspended solid which has been existed at the upstream of the observed point or which has been aggregated near the observed point. In a phase that the total volume concentration is high, the volume concentration of 200- 460 micron is very high, and it is induced to the flocculation in high water slack. While, the volume concentration below 20μm is high, and those of 30-150 micron are very low. It is supposed that suspended solid with above-mentioned diameter may relate to the flocculation or may be broken up with increasing of velocity gradient(shear).