Analysis of the response to recharge in Alpujarride carbonates via a hydrodynamic, hydrochemical and isotopic study of the Carcabal spring at La Peza, Granada

We have studied the hydrodynamic, physical-chemical and isotopic characteristics of a spring associated with a smallish aquifer located in the province of Granada on the northern slope of the Sierra Nevada. The aquifer, composed of carbonate rocks belonging to the Alpujarride domain in the Betic Cordillera, shows considerable surface karstification, with presence of large sinkholes, which is quite unusual in this type of rock. Our study was based on flow and climate data obtained between the years 2006 and 2008 at a gauging station and a weather station built by the Geological Survey of Spain, together with physical-chemical data collected during 2008. The hydrodynamic study concludes that the aquifer behaves as a karstic aquifer during winter, with a well developed pipeline network. In the spring it behaves as a complex karst aquifer. From the hydrochemical and isotopic data it is possible to differentiate the water that flows quickly through the aquifer in periods coinciding with abundant recharge of the water stored in the saturated zone. Our results provide important information about an area where there are a very large number of carbonate aquifers that have hardly been little studied to date due to the complexity of their drainage systems, which are very difficult to monitor, and often a complete lack of meteorological data for their immediate surroundings. (Author) 29 refs.