IDENTIFYING SPRINGS IN FLORIDA'S BIG BEND USING THERMOGRAPHY AND OTHER METHODS

Twenty-seven new springs and spring groups were cataloged by the authors in the 14,600-acre Spring Creek Unit of the Big Bend Wildlife Management Area in Taylor County, Florida. Utilizing ArcMap™ software and Taylor County thermography data fifty points of interest (i.e., thermal hotspots) were identified. The authors visited thirty-three of these points by boat or on foot, and twelve springs (four previously cataloged) were confirmed. Using aerial photography and field observation, another eleven unknown springs/seeps were cataloged by the authors in areas without thermography data. Using video and photographs acquired with a drone, eight additional springs were identified, but not visited. One of these was a point of interest identified using thermographic data.

At each spring location visited, general descriptions, estimates of discharge, and photographs were obtained. Field water quality parameters (dissolved oxygen, pH, specific conductance, and temperature) and water samples were obtained at eight springs and analyzed for metals and nutrients. The water quality data show half of the sampled springs have a saline influence and are discharging a mix of fresh and marine waters. The authors attempted to sample two offshore springs, a decline in discharge at these springs precluded obtaining representative samples even at negative tidal cycles.

Based on observations made during the project, there are additional springs that were not verified due to difficultly of access and spring discharge fluctuations caused by changes in hydrological conditions and tidal influences.

Remote sensing is a useful tool for locating springs in difficult to access coastal terrains and can help identify areas of groundwater discharge that may be masked by tidal influences, dense vegetation, or are otherwise easy to overlook.