Comparison of methods for analysis of the transverse and vertical circulation contributions to the longitudinal advective salt flux in estuaries

Three different sampling designs, based upon the manner in which the total cross-sectional area is decomposed into sub-areas, are explored for their applicability to assessing the transverse and vertical variations of properties in an estuary cross-section. Three hypotheses on the nature of the distribution are used to test the designs.

The procedures are applied to Southampton Water where it is found that although both the salinity and velocity have important transverse and vertical variations, the longitudinal advective salt flux is almost totally due to their vertical deviations. This results, which contrasts with previous analyses, follows from the effect of gravity in vertically stratifying both the salinity and velocity distributions.