INFLUENCE OF THE UNSTEADY CHANGE OF TIDAL RANGE UPON THE SALINITY INTRUSION IN TIDAL ESTUARINE RIVERS

Abstract

In this paper, the effects of the change in a tidal range on salinity intrusion in a tidal estuary were investigated with an experimental set-up which can realize an arbitrary change of tide and the transition of the mixing type.Then a vertically 2-dimensional numerical simulation of the above experimental results was carried out in order to verify its predictive ability. As a result, the following findings were obtained;1) When the change in the salinity intrusion length due to the change in the tidal range spends a relatively long time for exchanging the fluid, salinity intrusion does not actually correspond to that of quasi-steady state and the change in salinity intrusion length has the phase shift compared with the tidal change.2) It is confirmed that the vertically 2-dimensional numerical model developed can reproduce the experimental results of the unsteady change in the salinity intrusion with a good accuracy.