Minimum Length of Salt Intrusion in Estuaries

Experiments on salt intrusion from a sea basin into a rectangular flume are described. Boundary conditions such as seawater density, tidal amplitude, and hydraulic resistance, have been varied. Minimum and maximum lengths of salt intrusion during a tidal cycle as functions of the varied quantities are presented. Dimensional analysis is applied to find correlations between the minimum length of salt intrusion and tidal quantities. Results indicate a relation between a nondimensional parameter containing the minimum length of salt intrusion, the depth and resistance coefficient, and three nondimensional parameters characterizing the tidal movement and containing the density difference between seawater and freshwater.