ABSTRACT
Understanding the role of the vadose zone is essential to accurately assess hydrogeological systems and their respective groundwater resources. The study area (Manteigas – Nave de Santo Antonio – Torre sector, Serra da Estrela Mountain, Central Portugal), presents specific geological, morphotectonic and climatic characteristics which influence the hydrogeological regime. The vadose zone has particular features that contribute to control both the quantity and the quality of the groundwater resources. The regional characterisation of this zone was carried out in terms of the structure, the soil, including the broad physical, chemical and mineralogical features and the soil hydraulics. The study included field work focused on geological and pedological features, soil permeability field tests, laboratory tests (including soil water retention at different pressure heads and clay mineralogy) and mathematical modelling. Water retention data were used to derive the parameters of van Genuchten’s water retention curve. Unsaturated hydraulic conductivity was estimated using the Gardner mathematical model.
