Recharge processes of karst massifs: examples from southern Italy

Recharge of karst aquifers occurs when rainfall (or snowmelt) infiltrationcrosses the soil mantle and percolates throughthe vadose zone. In karst environments, the infiltration can occur in both concentrated and diffuse forms. In several areas of the Mediterranean, karst massifs are important sources of drinking water. In southern Italy, karst massifs are generally characterized by wide endorheicbasins with seasonal lakes, which constitute large parts of the spring catchments. The origin of these endorheic basins is related to tectonism during the upper Pliocene-Pleistocene epocs and subsequent erosion and karstification. These endorheic basins,constitute the most important recharge areas of karst massifs in central-southern Italy, and have been designated as groundwater protection areas. This study focuses on the karst massifs of the Picentini Mountains which is characterized by rugged, steep landscape and comprised of mainly of dolostone and limestone. These karst massifs feed many basal karst springs with discharges up to thousands of liters for second, and constitute the main water resource in the region of Campania. The hydrological processes in these basins are simulated using a Geographic Information System (GIS) based modelon an annual scale.The results of the annual scale model have been used to successfully calibrate a daily time step model of infiltration and run off.