Karst Water Inventories Using Thermography

An airborne thermal camera was used to locate springs, swallets, and caves in a karst watershed. The detector was an imaging infrared camera with a temperature sensitivity of approximately 0.10°C. The resolution on the ground was a fraction of a meter with a total field of view of one hectare. A bird in flight was clearly visible on one image sequence. We believe that this camera is the most sensitive one ever used to detect hydrological features in karst watersheds. The data acquisition system also provided global positioning system (GPS) data so that the imagery could be correlated with ground positions. So fir, three new springs and a new cave were located with the imagery alone. With the GPS data and the imagery, seven additional hydrological features detected on the imagery were pinpointed and await field identification.