ABSTRACT
Karst springs provide information that is essential for characterising hydrogeological behaviour and the optimum management and exploitation of karst aquifers. Hydrochemical, hydrodynamic and intrinsic natural fluorescence (IF) data obtained from the karst spring waters of El Burgo and Fuensanta (southern Spain) illustrate the hydrogeological behaviour within the Sierra Blanquilla and Sierra Hidalga aquifers. Discharge variations at Fuensanta are faster, but less pronounced than at El Burgo. Electrical conductivity (EC) time series and hydrochemical monitoring suggest that there is a more highly developed karst network in the system drained by Fuensanta. EC at El Burgo varies according to TAC, Ca2+, Cl− and total organic carbon (TOC) contents, while SO2−4 and Mg
2+ vary inversely. Fuensanta presents wider variations in most chemical components and TOC, in accordance with its functioning as a conduit flow system. The hydrochemical data indicate different degrees of functional karstification. IF time variations at Fuensanta suggest a source of organic matter (higher TOC and IF peaks) of surficial origin (runoff infiltration) during high water periods. All these observations need to be confirmed by tracer tests and isotopic studies to reinforce the above hypotheses.
