Reprint from Transactions, American Geophysical Union, V. 36, Number 4, August 1955.Includes bibliographical references.The mechanism by which the tidal changes propagate salinity into the Delta channels and the manner in which this propagation is opposed by the fresh water stream flows are expressed in mathematical form. Solutions of the basic differential equation are given which are suitable for computation of salinity changes and a method of computation is described. As an example of the use of these methods they are applied to the historical records to determine a depletion curve for the Delta by using the observed salinities as an indicator and finding the flows out of the Delta which were necessary to hold the salinities to the observed amounts. While the primary usefulness of this depletion curve is to form a basis for further estimates of ocean salinity encroachment, it is compared to use curves derived from independent sources
