Poster presentation: Evaluating heat tracing models in a pool-riffle-pool sequence, GSA Portland 2009

gsaPoster2009A pool-riffle-pool sequence in streambed morphology is thought to drive hyporheic downwelling near the head of the riffle and upwelling at the tail of the riffle and head of the lower pool. Heat tracing is a potentially useful method to characterize these hyporheic flow paths. A pool-riffle-pool sequence within Jaramillo Creek, Valles Caldera National Preserve, New Mexico was instrumented with a two dimensional vertical array of thermistors during the summers of 2008 and 2009. Three one-dimensional analytical heat transport models (Hatch et al 2006, Keery et al 2007, and Schmidt et al 2007) were used to individually interpret sections of the pool-riffle-pool sequence to quantify vertical fluid fluxes. The modeled fluxes were then compared to values obtained from vertical hydraulic gradient and hydraulic conductivity measurements. The fluxes estimated by the heat tracing methods exhibit a trend that partly follows the conceptual model of a pool-riffle-pool sequence. The directly calculated fluxes mostly agree with heat tracing based estimates. The deviation in flux distribution from the conceptual “downwelling-upwelling” model is partly due to the dominantly loosing conditions at the study site. Moreover, varying assumptions concerning boundary conditions and physical properties of the streambed that are intrinsic to the analytical models produce somewhat inconsistent results between methods. Careful selection of a model for heat tracing is vital to obtaining accurate fluid flux estimates. Click on the image of the poster to download a PDF of the poster.

[1] Bredehoeft, J. D., and I. S. Papaopulos. 1965. Rates of vertical groundwater
movement estimated from the Earth’s thermal profile. Water Resources Research
1: 325-328. (PDF link)
[2] Hatch, C. E., A. T. Fisher, J. S. Revenaugh, J. Constantz, and C. Ruehl. 2006.
Quantifying surface water-groundwater interactions using time series analysis
of streambed thermal records: Method development. Water Resources Research 42. (PDF link)
[3] Keery, J., A. Binley, N. Crook, and J. W. N. Smith. 2007. Temporal and spatial variability
of groundwater-surface water fluxes: Development and application of an analytical
method using temperature time series. Journal of Hydrology 336: 1-554 16. (PDF link)
[4] Schmidt, C., B. Conant, M. Bayer-Raich, and M. Schirmer. 2007. Evaluation and
field-scale application of an analytical method to quantify groundwater discharge
using mapped streambed temperatures. Journal of Hydrology 347: 292-307. (PDF link)