Depths in the model were idealized by three horizontal surfaces located
at elevations corresponding to depths of el 0, el -30, and el -60 with vertical
transitions between the three depths. The glass bottom of the flow table served
as the el -60 contour. Figure 14 shows the small-area model being cut out of
3.81-cm (1.5-in.-) thick Plexiglas, and Figure 15 illustrates the idealized
bathymetry in the completed small-area model as viewed from the seaward end.
Contours are shown on Figure 16 where the red lines represent the shoreline,
the blue lines are the el 0, and the green lines are the el -30 depths. As
mentioned, the bottom of the flow table represents the el -60 depth. The nearly
right-angle bend in the modeled region resulted in the model being built at a size
smaller than originally intended to allow a more direct inflow path while still
accommodating outflow. The model was designed to be reversed on the table for
ebb and flood conditions as illustrated in Figure 17. Operating procedures for the
small-area model are the same as described for the large-area model.
Small-Area Model Observations
The small-area model was also tested extensively during the May 2002 visit
by Alaska District engineers. Flow patterns recognized in the large-area model
were replicated in the small-area model to see if the more detailed (but still
idealized) bathymetry altered any of the flow patterns substantially.
The small area model produced similar flow patterns as the large-area model,
particularly the three large flow separation and eddy formation features at Point
Woronzof, Point MacKenzie, and Cairn Point. The bottom crosscurrent flowing
diagonally between Point Woronzof and Port MacKenzie was also evident.
The small-area model did not replicate the boundaries as far upstream as the