Multi-Pronged Data Collection Strategy for a Fusion Approach to Characterize Karst Aquifers

Karst aquifers supply water for one-fourth of the global population. Understanding karst aquifers is challenging, however, because they often contain a complex network of fractures and conduits that result from dissolution of bedrock, typically carbonate rocks. Because of the complex nature of karst systems, many methods (e.g., direct conduit mapping, tracer tests, geophysical investigations, etc.) have been implemented to characterize karst aquifer systems. These methods provide valuable information but with significant limitations, especially in characterizing small fractures and conduits that are critical to water flow and contaminant transport. We are developing a complementary data-fusion approach that combines data collected from various traditional and innovative field approaches into a geostatistical-based inversion framework to characterize distribution and morphology of fractures and conduits in great detail. This multi-pronged data collection effort is taking place in the Cane Run Royal Spring basin in central Kentucky. The overall data collection strategy is centered on monitoring karst aquifer responses to natural and human-induced stimuli. The data collection methods being used include hydraulic tomography, river and conduit stage tomography, electrical resistivity tomography, tracer tests, and lightning tomography. Water chemistry, sediments, and stable isotope data have also been collected. The fusion approach will use the data from various tomographic surveys to characterize fractures and conduits in karst aquifers in a cost-effective manner and, in turn, to improve our understanding of and prediction of flow and solute transport in the karst aquifers. The validity of the aquifer characterization will be evaluated with a separate model using field collected water level, water chemistry, tracer, and stable isotope data.