Field Test of the In Situ Permeable Ground Water Flow Sensor

Abstract

Two in situ permeable flow sensors, recently developed at Sandia National Laboratories, were field tested at the Brazos River Hydrologic Field Site near College Station, Texas. The flow sensors use a thermal perturbation technique to quantify the magnitude and direction of ground water flow in three dimensions. Two aquifer pumping tests lasting eight and 13 days were used to field test the flow sensors. Components of ground water flow as determined from piezometer gradient measurements were compared with ground water flow components derived from the 3‐D flow sensors. The changes in velocity magnitude and direction of ground water flow induced by the pump were evaluated using flow sensor data and piezometric analyses. Flow sensor performance closely matched piezometric analysis results. Ground water flow direction (azimuth), as measured by the flow sensors and derived in the piezometric analysis, predicted the position of the pumping well accurately. Ground water flow velocities measured by the flow sensors compared well to velocities derived in the piezometric analysis. A significant delay in flow sensor response to relatively rapid changes in ground water flow was observed. Preliminary tests indicate that the in situ permeable flow sensor provides accurate and timely information on the velocity magnitude and direction of ground water flow.

Accuracy of Flowmeters Measuring Horizontal Groundwater Flow in an Unconsolidated Aquifer Simulator

“…Spinner, heat‐pulse, and electromagnetic flowmeters intended to exclusively measure vertical flow in the borehole were not examined by this study. Similarly, other flowmeters and methods that may be capable of measuring horizontal and three‐dimensional (3D)‐flow are described elsewhere (Momii et al 1993; Alden and Munster 1997).…”

A 3D analysis algorithm to improve interpretation of heat pulse sensor results for the determination of small-scale flow directions and velocities in the hyporheic zone

“…In several studies, heat has been used as a natural tracer to localize water exchange zones (Selker et al, 2006) and to quantify vertical flow with a one-dimensional (1D) solution of the heat transport equation Constantz, 2003, 2004;Schmidt et al, 2006;Anibas et al, 2009;Schornberg et al, 2010). Furthermore, different methods employing heat pulse injection techniques were applied to measure groundwater flow velocity (Melville et al, 1985;Ballard, 1996;Ballard et al, 1996;Alden and Munster, 1997), soil water flux (Kawanishi, 1983;Ren et al, 2000;Yang and Jones, 2009;Kamai et al, 2010) and also hyporheic flow (Greswell, 2005;Greswell et al, 2008Greswell et al, , 2009) two-dimensionally (2D). Few studies, however, have utilized heat as a tracer of hyporheic flow in three dimensions.…”

A heat pulse technique for the determination of small‐scale flow directions and flow velocities in the streambed of sand‐bed streams

“…The first sensor for 1D measurement of soil water flow rates in saturated soils, which had to be aligned parallel to the flow direction, was a 7‐cm‐long cylindric device with a heater in the middle section and two thermocouples at each end (Byrne et al , 1967). Ballard (1996); Ballard et al (1996); Alden and Munster (1997); Su et al (2006) developed and tested a larger 75‐cm‐long 5‐cm diameter device with the heater as a thin film covering the whole surface. Thirty temperature sensors arranged on the surface were used to determine magnitude and direction of 3D groundwater flow.…”