Example
of the Anisotropic Nature of Precipitation in the GVRD
As
an example, consider Richmond. Precipitation here is not likely significantly
influenced by the elevation of regions to the east, west or even south. However,
the increasing elevation to the north is definitely important. The presence
of the North Shore Mountains may not influence precipitation in Richmond as
strongly as it does nearer locations, but it still holds significant influence.
Precipitation in Richmond, and indeed most of the GVRD, would be significantly
less if the North Shore Mountains were replaced by a plain. The influence on
Richmond’s precipitation is not as great as Vancouver or the North Shore,
but it is still present and important. By returning to the concept of a landscape
with a perfectly planar slope in the north-south direction (on the windward
side), it is much easier to visualize that the precipitation at any point will
be influenced very little by the elevation to its east, west and south, but
considerably affected by that to its north. The elevation of any region will
have the greatest effect on precipitation over regions further down slope. As
previously discussed, the topography of the Lower Mainland, though still far
from matching this idealized surface, does share some similar features when
examined at a small scale.
