Hidrogeología del delta del Río Adra

Abstract

[ES] El delta del río Adra, en sentido geográfico, constituye un sistema acuífero de geometría compleja integrado por materiales detríticos neógeno- cuateroarios, cuyo sustrato impermeable está formado por metapelitas alpujárrides. Con una precipitación media anual de 400 mm y temperatura superior a 18 °C se estima una lluvia útil media superior a 100 mm/año. Sus aguas, de calidad mediocre o mala, tanto para uso doméstico como agrícola, presentan facies sulfatada magnésicocálcica o clourada sódica y contenido total en sales disueltas comprendido entre 1 y 4 g/l. La principal fuente de alimentación procede de la recarga a partir del río Adra, con el que guarda estrecha relación hidráulica. Este sistema es actualmente excedentario en recursos y susceptible de un mayor aprovechamiento, en un área en donde la escasez de agua constituye el principal elemento limitativo del desarrollo.

[EN] The geographical delta of the Adra River, comprises a complex aquiferal system running through neogene-quaternary materials, which in turn overlie impermeable Alpujarride metapellitic rocks. The mean average rainfall is sorne 400 mm, the average temperature above 18°C, and it is calculated that, including infiltration and runoff, the annual rainwater amounts to more than 100 mm. The groundwater in general ranges from bad to mediocre in quality, both for domestic and agricultural use, containing as it does calcic-magnesium sulpbates and/or sodium cblorate to quantities of 1 to 4 gil in solution. The principal source of recharge for the system is from filtration through tbe permeable bed of the Adra River, with wbich in hydraulic terms it is closely related. The resources of this system at the moment exceed the demand being put on them and it would be possible to obtain greater benefits from it in an area where a general shortage of water is one of the main factors limiting development.