Tracer tests in karst hydrogeology and speleology

INTRODUCTION Tracing techniques can be used in all types of hydrological and hydrogeological environments to obtain information about water movement and contaminant transport (Kass, 1998). However, the methodology of water tracing was initially developed for the investigation of karst aquifers, and is still most widely used in karst, where groundwater trajectories are not immediately apparent. Tracer tests, combined with geological and hydrological observations, are the most powerful method to delineate the catchment areas of karst springs, even in complicated geological and topographic settings (e.g. Goldscheider, 2005). Tracer tests in caves are mostly used to identify active conduit networks, although caves also provide natural experimental and monitoring sites inside the aquifer (Benischke et al., 2007).