Combined use of natural and artificial tracers to determine the hydrogeological functioning of a karst aquifer: the Villanueva del Rosario system (Andalusia, southern Spain)Utilisation combine des traceurs naturels et artificiels pour déterminer le fonctionnement hydrogéologique d’un aquifère karstique: le système de Villanueva de Rosario (Andalousie, Sud de l’Espagne)El uso combinado de trazadores naturales y artificiales para determinar el funcionamiento hidrogeológico de un acuífero kárstico: El sistema de Villanueva del Rosario (Andalucía, sur de España)联合应用天然和人工示踪剂确定岩溶含水层的水文地质功能:(西班牙南部安达卢西亚)Villanueva del Rosario系统O uso combinado de traçadores naturais e artificiais para determinar o funcionamento hidrogeológico de um aquífero cársico: o sistema de Villanueva del Rosario (Andaluzia, sul da Espanha)

Analysis of natural responses of karst springs provides information on the behavior of the aquifers they drain. Detailed monitoring and qualitative and quantitative analyses of natural responses, and environmental—total organic carbon (TOC), NO3−, Cl− and intrinsic fluorescence—and artificial (fluorescent dye) tracers, in the water drained by Villanueva del Rosario spring (southern Spain), suggest the existence of a conduit flow system with rapid flows and very short transit times of water through the aquifer. This is in agreement with uranine and eosin breakthrough curves and with simple numerical models done using these data. However, due to the low capacity for natural regulation, not all the recharge effects are simultaneously transmitted to the spring water; given a single input, the system modulates and transfers hydrodynamic variations faster than variations of chemical composition and of water temperature. Additionally, time lags between maximum concentrations of natural and artificial tracers show that the global system response (including diffuse infiltration) is faster and more sensitive than that produced from infiltration concentrated at a single point on the surface (sinkholes).