Mya Symington-St John
March 20,2022
You are helping a small yachting company understand the effects on longshore transport
of building a new harbor. Below is a sketch of how most of the waves approach the shore.
The lines represent the wave crests.
1.
In which direction would longshore transport carry water and sand?
To the left with the drift sector spanning the wave crests
The small yachting company is constructing a breakwater that extends out from the beach
at an angle (sketch below).
Recall how bays create a low-energy wave environment (right figure above). This is the
shape of the beach/breakwater west (left) of the breakwater.
2.
If we assume that we have created a low-wave-energy environment west of the
breakwater, what will happen to the sand in the longshore current?
The sand will be deposited to the left of the breakwater
3.
If sand is deposited west of the breakwater, what happens to the sand amount in
the longshore current and how would that affect beaches east of the harbor?
Since the sand is being deposited west, there will be less sand in the longshore current
and thus the beaches east of the harbor will undergo erosion
4.
As more sand is deposited on the west side of the new breakwater, what will
eventually happen?
The east side of the breakwater will become the new drift sector
5.
Where will the new closest low-wave-energy area be located and what effect will
that have on the harbor?
The harbor on the east side will now be the new drift sector putting the new closest low
wave energy area after the harbor thus helping fix the previous erosion near the harbor
Erosion of sandy shores
