Mass balance and spectral analysis applied to Karst hydrologie networks

Underground karst drainage systems can be studied by the input‐output relations of rivers that flow through them. First, tracers enable the quantity of water at a sink that flows to a specific spring, and the fraction of a given spring derived from a sink, to be calculated. Second, when these methods are not applicable, cross‐covariance and cross‐spectral transfer function analysis can be used to examine input‐output stage records. These give information about the vadose and/or phreatic nature of the system. An inaccessible karst drainage system in western Alberta has a tracer flow‐through time of +80 to +130 hours and a positively skewed cross covariance of +70 to +124 hours; therefore the cave is not completely water filled. Additional unknown inputs are substantiated by a negatively peaking cross covariance.