Impacts of human activities on recharge in a multilayered semiarid aquifer (Campo de Cartagena, SE Spain)

摘要: The development of intense agriculture in semiarid areas modifies intensity and spatial distribution groundwater recharge by summing irrigation return flow to limited rainfall infiltration. Environmental tracers provide key information, but their interpretation is complicated more complex patterns. In multilayered aquifers, the real origin samples hard assess because local mixing processes occurring inside long-screened boreholes. We use environmental (14C, 13C, 2H, 18O, 3H) investigate long-term evolution five-layer Campo de Cartagena aquifer South-Eastern Spain, addition high-resolution temperature loggings identify depth groundwater. Despite background, this methodology allowed a reliable geochemistry provided better understanding tritium method did not give good quantitative results high variability signal remained an excellent indicator recent recharge. Nonetheless, both pre-anthropization post-anthropization regime could be identified quantified radiocarbon. Before agriculture, varied from 17 mm.year-1 at mountain ranges 6 mm.year-1 plain, whereas mean annual about 300 mm. response increase agricultural activity, fluxes plain were amplified nowadays reach up 210 mm.year-1 irrigated areas. These values are strengthened global water budget unsaturated zone studies. Copyright © 2013 John Wiley & Sons, Ltd.