Water Stewardship Information Sources

Citation Reid, DE, Hickin, EJ and Babakaiff, SC. 2010. Low-flow hydraulic geometry of small, steep mountain streams in southwest British Columbia. Geomorphology 122:39-55.
Organization SFU
URL http://www.sfu.ca/~hickin/PDF%20Library/Reid%20H%20&%20B%202010.pdf
Abstract/Description or Keywords This investigation explores the at-a-station hydraulic geometry (AHG) of small, steep mountain streams at
low discharge. Thirteen reaches in five tributaries of Chilliwack River, British Columbia, ranging in size from
12 to 77 km2 are examined. The resulting data set is composed of eight to twelve measurements of watersurface
width, mean depth, and mean velocity at each of 61 cross sections or 625 unique combinations of the
three variables. Mean velocity in a given cross section responds most rapidly to changing discharge, and 31 of
the 61 cross sections have velocity exponents that are greater than the water-surface width and mean-depth
exponents combined. The velocity exponent (m) averages 0.51, while the mean water-surface width
exponent (b) and mean-depth exponent (f) average 0.20 and 0.29, respectively. Somewhat surprisingly, the
AHG of steep mountain streams can be reasonably predicted from just a few measurements of the primary
flow variables and stream discharge. While conditions at the cross section appear predictable from a few
measurements, extrapolating the results from one cross section to another in the same reach involves large
errors. The section-to-section variability of the exponents and coefficients, even when they are located in
similar channel units such as riffles, prevents accurate extrapolation to unmeasured cross sections.
Information Type article
Regional Watershed Lower Fraser
Sub-watershed if known Chilliwack River
Aquifer #
Project status
Contact Name Donald Reid
Contact Email [email protected]