Wednesday, August 21, 2013

Price Road

Many small beaches on Salt Spring are swash-aligned pockets, completely contained by bedrock points.  Beddis Beach (Gravel Beach 2008), a short distance south of this one, is a great nearby example. 

This one off Price Road is not a pocket beach. The shoreline orientation changes and the beach becomes a little more swash-aligned, which allows a wider beach to build, but there's nothing at the distal end to keep it from spilling around the corner.  A small stream delta acts like a groin, and there's a small rock groin, too, but these simply the slow the beach down, they don't stop it.

The sediment on this beach appears to come from the shoreline to the south - eroding banks and a small stream mouth.

Farther downdrift the beach is coarse and narrow, except where a couple of groins attempt to trap the rapidly moving finer material. Half a mile farther north, where the coastline turns west again, the beach itself just keeps going strait, forming a small spit (a site for a paddle trip in a future year).

AERIAL VIEW (Google Maps)

I think one lesson here is that in this highly oblique wave environment (the west shore of Ganges Harbor), the width of the beach (the volume of the beach) is a function of the speed with which sediment passes through - which in turn is a function of the orientation of the beach.

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