Water Stewardship Information Sources
| ID | 1135 |
|---|---|
| Citation | Leach, J.A. and Moore, R.D. 2011. Stream temperature dynamics in two hydrogeomorphically distinct reaches. Hydrological Processes 25: 679-690, DOI: 10.1002/hyp.7854. |
| Organization | UBC |
| URL | http://onlinelibrary.wiley.com/doi/10.1002/hyp.7854/abstract |
| Abstract/Description or Keywords | Keywords: stream temperature;surface-subsurface interactions;energy budget;hyporheic exchange;groundwater;thermal regime;bed heat conduction Abstract The objective of this study was to analyse stream temperature variability during summer in relation to both surface heat exchanges and reach-scale hydrology for two hydrogeomorphically distinct reaches. The study focused on a 1ﾷ5-km wildfire-disturbed reach of Fishtrap Creek located north of Kamloops, British Columbia. Streamflow measurements and longitudinal surveys of electrical conductivity and water chemistry indicated that the upper 750 m of the study reach was dominated by flow losses. A spring discharged into the stream at 750 m below the upper reach boundary. Below the spring, the stream was neutral to losing on three measurement days, but gained flow on a fourth day that followed a rain event. Continuous stream temperature measurements typically revealed a downstream warming along the upper 750 m of the study reach on summer days, followed by a pronounced cooling associated with the spring, with little downstream change below the spring. Modelled surface energy exchanges were similar over the upper and lower sub-reaches, and thus cannot explain the differences in longitudinal temperature patterns. Application of a Lagrangian stream temperature model provided reasonably accurate predictions for the upper sub-reach. For the lower sub-reach, accurate prediction required specification of concurrent flow losses and gains as a hydrological boundary condition. These findings are consistent with differences in the hydrogeomorphology of the upper and lower sub-reaches. The modelling exercise indicated that substantial errors in predicted stream temperature can occur by representing stream-surface exchange as a reach-averaged one-directional flux computed from differences in streamflow between the upper and lower reach boundaries. Further research should focus on reliable methods for quantifying spatial variations in reach-scale hydrology. |
| Information Type | article |
| Regional Watershed | North Thompson |
| Sub-watershed if known | Fishtrap Creek |
| Aquifer # | |
| Comments | |
| Project status | complete |
| Contact Name | Dan Moore |
| Contact Email | [email protected] |