Resources assessment of a small karstic mediterranean aquifer (South-Eastern, Spain)

Groundwater from small aquifer systems is frequently used for urban supply in southeastern Spain. Aquifers such as the Ventos system, located in Mediterranean semiarid environments, are sensitive to climatic and anthropogenic changes. Many of them have been severely depleted due to intensive pumping. Drawdowns in the Ventos aquifer amount to approximately 80m over the last three decades. Adequate knowledge of groundwater resources is necessary for water planners and managers to guarantee suitable abstraction. This paper presents a methodology to estimate groundwater recharge in these kinds of quick-response semiarid karst aquifers. A distributed model has been used to evaluate the fraction of rainfall that ultimately results in aquifer recharge, as well as the correlation between the magnitude of rainfall events and infiltration rates. Modelling results are then compared with direct observations of the recharge processes and discussed to evaluate the implications of time scales