For the given river stage discharge (or for each /estuary/ocean/ ambient velocity field) combination to be analyzed, assemble plots showing the cross-sections at the discharge and several downstream locations.
Examine these to determine an "equivalent rectangular cross-sectional area." Try to preserve essential details of port distance to vertical and then lateral boundaries, because they will control discharge stability and boundary interaction. Very shallow bank areas or shallow floodways may be neglected as unimportant for effluent transport.


