Theoretical considerations on the motion of salt and fresh water

Abstract

This paper gives a survey of the theoretical investigations in Holland on the motion of salt and fresh water in estuaries, locks, etc. The insight gained is set forth, and also questions yet unsolved are mentioned. First the long wave phenomena in the interface of two sharply separated liquids are treated, and in connection herewith, the cases of critical flow. The saltwedge in a river without tides and the penetration of salt through locks are discussed. Next, the stability of the interface is considered. The saltwedge with disturbed interface in a tidal river (corrupted saltwedge) and the desalting of a canal by a sluice with a screen are discussed. Finally the mixing processes in a brackish water region are classified. The mixing in a corrupted tidal saltwedge is discussed and the intrusion of salt in an estuary. It appears that the main agent of mixing in estuaries is the exchange of water between the channel and storing basins, shoals, etc.