Handheld Thermal Imaging Cameras for Groundwater/Surface-Water Interaction Studies
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USGS scientists are using high-resolution handheld thermal imaging cameras in groundwater/surface-water interaction studies and other investigations. These cameras are used to quickly locate and characterize thermal anomalies in streams, lakes, and adjacent structures. Variations in temperature can be used to track the heat carried by flowing water, such groundwater discharge into a stream.
Overview
Although airborne and satellite thermal imaging for water-resources studies is common, the availability of robust handheld thermal imaging tools in support of USGS groundwater studies is relatively new. The cameras allow hydrologists to rapidly image real-time variations in temperature at high resolution in the field at scales from a few centimeters to tens of meters. The information can be used to:
- localize groundwater discharge,
- help characterize local hydrogeologic conditions, and
- optimize sampling and monitoring locations.
The small size of the cameras makes them convenient tools for studies in dense urban settings as well as remote field sites (fig. 1). Potential field applications are being explored within the USGS Water Resources Mission Area and in interdisciplinary work across the USGS.
Heat as a Tracer of Water Movement Near Streams
Temperature has long been recognized as an important water-quality parameter. Differences between temperatures in a stream and surrounding sediments can be analyzed to trace the movement of groundwater to and from streams, and to better understand the magnitudes and mechanisms of stream/groundwater (hyporheic zone) exchanges. Figures 2 and 3 show how thermal imaging can be used to rapidly identify, visualize, and quantify differences in water temperature that may indicate groundwater discharging to the surface. To learn more about use of heat as a tracer, see "Heat as a tool for studying studying the movement of ground water near streams."
Thermal Imaging Camera Use Examples
The USGS Water Resources Mission Area has sponsored handheld thermal imaging camera technology demonstration and evaluation projects by USGS researchers in around the Nation.
References & Related USGS Publications
Briggs, M.A., Voytek, E.B., Day-Lewis, F.D, Rosenberry, D.O., and Lane, J.W., 2013, The hydrodynamic controls on thermal refugia for endangered mussels in the Delaware River : Environmental Sciences and Technology: v. 47, no. 20, p. 11423-11431. doi:10.1021/es4018893.
Additional Resources