Ground-Penetrating Radar Hyporheic Project

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Project Title:Utilizing Ground-Penetrating Radar to Determine the Extent of the Hyporheic Zone in Mountain Streams
Project Duration: 1-Sep-2004 - 31-Aug-2007
John Bradford (Boise State University)
Michael Gooseff (Penn State University)
Jim McNamara (Boise State University)
Overview: We are investigating the potential to use ground-penetrating radar techniques (multi-offset data acquisition, cross borehole tomography) to detect stream ionic tracers (dissolved salt) in the hyporheic zones of mountain streams. Specifically, our field sites are in the Sawtooth Mountains of Idaho.

As a proof-of-concept project, we expect that the exchange of salt-labelled stream water into the hyporheic zone will modify the dielectric properties of hyporheic water enough to be detectable with GPR and resistivity measurements.

At right is an image of the inflow delta of Springs Cr. into Bull Trout Lake.
Bull Trout Lake area
Below are pictures from our first field campaign in July, 2005.
After choosing our site, a tall dune bounded by pools, we had to install boreholes to 2m depth.
transect 1
Our completed transect #2 (looking downstream) consisted of 3 boreholes and 2 piezometer sets. Piezometers are white pvc tubes at depths of ~20cm and ~40cm. The dark spot in the foreground is organic litter collected in the pool upstream of the dune. Transect #1 was set up across the pool just upstream of Tranect #2 seen here.
transect 2
Transect #3 was completed with piezometers only, no boreholes. Transect #4, over a pool, is in the background. Note the pool in the foreground, dune at Transect #3, and pool in the background.
transect 1 during experiment
We also made resistivity measurements in the subsurface during the stream tracer experiments. Note that we co-injected dissolved NaCl and rhodamine WT dye. Also note Transect #1 at the upstream (foreground) wooden plank.
injection point
In order to achieve our target increase of specific conductance in the stream of 100 uS/cm, we had to use 2 injection pumps. Mixing in the downstream bend and subsequent pool was efficient.
transect 1 during experiment
Transect #1 (left) and #2 (right) during the experiment. The green wires are used for subsurface resistivity measurements.
Kristen at transect 1
Kristen working with the cross-borehole equipment.
Dr. Bradford at transect 1
John works the borehole on the opposite bank.

Click on this link for pictures from our first field campaign in late September 2007.

Undergraduate Students:
Kristen Schmidt (CSM)

Graduate Students:
Troy Brosten (PhD student, BSU)

Conference Presentations:
Bradford, JH, MN Gooseff, and JP McNamara. 2006. Utilizing ground-penetrating radar and solute tracer experiments to image the extent of the hyporheic zone in mountain streamsUSDA-CREES National Water Conference 2006, San Antonio, TX.

Current weather in the Sawtooth Mountains Area:
Click for Stanley, ID Forecast
Current Weather at Banner Summit, ID
(from the National Weather Service in Pocatello, ID)
If this is blank, the weather station is not responding.

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This project is funded through the United States Department of Agriculture's National Research Initiative.
Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the USDA.

This page was created on 17-Aug-2005.
This page was last updated on 25-Oct-2009.