ABSTRACT
The location of springs in karst areas is often complicated by the discharge points being submerged in reservoirs or streams. IT Corporation was contracted by the U.S. Army Environmental Center to perform a comprehensive karst investigation at Volunteer Army Ammunition Plant in Hamilton County, Tennessee. However, most of the area where springs were expected to discharge was covered by TVA’s Chickamauga Reservoir in the 1940s. Based upon pre-dam maps and interviews with residents who lived in the area before the dam was built, several springs were expected to discharge into the Reservoir.
Thermal infrared (TIR) thermography has had extensive applications in military and government remote sensing but has had limited use in environmental applications because of high cost and extensive post processing. As costs are reduced and post-processing eliminated, a growing number of commercial companies now offer TIR services. TIR imaging was chosen as an appropriate application for this study because the discharge points are submerged. It was hypothesized that if an aerial TIR survey was conducted during late winter when water temperatures in the reservoir were at a minimum, the warmer spring water entering the reservoir would rise and appear as “hot-spots” on the thermal images.
The TIR survey was used to locate 15 submerged springs, most of which were confirmed by use of dye tracing techniques to discharge groundwater originating at the facility. TIR surveys can be an important tool in a karst investigation and should be considered in areas where submerged springs are suspected. Had this technology not been applied, these springs would have remained undetected, reducing the effectiveness of the karst study.
