La evaluación de la recarga como contribución al conocimiento hidrogeológico del acuífero carbonático de la Sierra de la Silla (Parque Natural de la Sierra de Grazalema, Cádiz)

Abstract

The Sierra de la Silla aquifer is the smallest (10 km2 of permeable outcrops) and westernmost aquifer forming part of the Grazalema Natural Park, situated to the NT of the Cádiz province. Previous works suggested its detailed investigation, due to the fact that it was supposed to be a representative subsystem of the karstic aquifers forming the hydrogeological unit of Sierra de Grazalema and, in addition, a straightforward system to be studied. The continuous monitoring of the flow rate of La Esparragosilla spring (though to represent the main discharge zone ofthe whole aquifer) and the comparison of such flow rate with diverse and independent estimations ofthe value ofthe recharge (daily soil water budget, chloride mass balance and the APLIS method), allowed us to prove that the recharge in this aquifer is markedly higher than the discharge ofthe cited spring. The distribution ofthe outflows through different sectors ofthe aquifer and its small dimensions hinders the development of organized conduit network, being this circumstance different from other known karstic aquifers of the Grazalema Natural Park. Tor these reasons, the hydrogeological functioning ofthe carbonate aquifer of Sierra de la Silla was found to be poorly representative ofthe majority ofthe carbonate aquifers ofSierra de Grazalema