Field Studies on the Motion of Salt Water Fronts in the Hiji Tidal River

Abstract

The upstream motion of saltwater fronts in tidal upper reach of the Hiji river has been observationally studied. The measurements were obtained at two fixed stations and several temporary sites apart from 200 m each other by boat. The profiles of density fronts were figured by lines at each mix-ture specified in percent and the velocities of their head during ebb and flood were evaluateded. The study shows that, the upstream velocities of flood water in well mixed are about 1, 000 times as great as that of tidal water rising. The un-stable state in interfacial transition layer through ebb are scrutinized by local Richardson number (Ri<1) at each layer in 10cm.