Implicaciones del funcionamiento de un acuífero carbonatado fisurado complejo (Sierra de Lujar, Granada) en la variabilidad hidroquímica de su descarga natural

Abstract

A hydrochemical study was carried out in a triassic carbonate aquifer located in a coastal mountain chain in the southern part of the Granada province (Sierra de Lújar, Alpujárride Complex, Betic Cordillera). This aquifer is made up of limestones and dolomites with marly and/or pelitic intercalations and sorne gypsum scattered or interbedded. Though the area is semid-arid, recharge by precipitation -rain or snow melt- is relatively high (over 600 mm/year) because of its mountainous nature up to near 1.900 m. The recharge of the aquifer also comes from the Guadalfeo river which crosses the permeable outcrops losing part of its stream flow. The carbonate rocks present dense microfissuration; the ground water regime is predominantly diffuse. The karstic forms are, in general, poorly developed either in the surface or at the level of speleological networks in the carbonate material. These characteristics influence the ground water chemistry, so the variability of physical-chemical parameters of water is very low, with single shaped histograms of these parameters. Although, in sorne points a larger variability was found related to mixing with streamwaters from the Guadalfeo river.