Inverse Estimation of Estuary Flux

Abstract

The velocity field of a shallow bay is strongly influenced by two factors; the tides and the fresh water flux from the estuaries within the bay. The tidal motions can be accurately measured because of its periodical and consistent nature. While the volume of fresh water disposed from the estuary into the bay can be monitored in general, however, to do it continuously is not a trivial matter. In the present study, a method has been developed to indirectly estimate the estuary flux by using the continuous observations of surface velocity field of the nearby coastal waters. The approach is based on the concept of “system identification” in which a continuous relationship is assumed such that the surface velocities can be expressed as Taylor series functions of the estuary flux. Based on a rigorous mathematical procedure, the estuary flux can be estimated from the measured surface velocities. The method was applied to a continuous surface velocity data sets from a CODAR system located at the Pearl River Estuary for estimating the time history of fresh water flux from the river exits.