Analysis of thermal gradients in hyporheic zones of arctic streams to determine flow dynamics

Open Access
Author:
Bakey, Christopher Edward
Graduate Program:
Civil Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
July 05, 2012
Committee Members:
  • Michael N Gooseff, Thesis Advisor
Keywords:
  • Hyporheic Zone
  • Arctic Streams
Abstract:
Current methods to calculate seepage in the hyporheic zone by using temperature time series are limited to a one-dimensional approach. Using arctic streams with a known boundary condition at the permafrost the temperature gradients are calculated in three-dimensions in the end of pools and the beginning of the next riffle. Matlab was used to calculated thermal gradients from raw temperature time series data. Matlab was also used to calculate one-dimensional seepage rates using the Hatch method. The strength of vertical temperature gradients was within the same order of magnitude at all locations during both collection periods. The strength of horizontal temperature gradients in riffles U1, U2 and U3 was stronger than those in pools D1, D2, D3. The horizontal temperature gradients were on the same order of magnitude as vertical temperature gradients at the sites U1, U2 and U3. This result suggests horizontal seepage could be as large as vertical seepage in riffles and that current one-dimensional approaches could underestimate overall seepage in riffles.