Integration of various data sources for transient groundwater modeling with spatio-temporally variable fluxes-Sardon study case, Spain

The dry season sap flow measurements of tree transpiration performed in the homogenous stands of Quercus ilex and Quercus pyrenaica indicated flux rates of 0.40 and 0.15 mm/d, respectively. The dry season tree transpiration for the entire catchment was ∼0.16 mm/d. The availability of dry season transpiration measurements considered as root groundwater uptake (Tg), allowed estimation of dry season catchment groundwater evaporation (Eg) as 0.48, 0.64, 0.39 mm/d for 1997, 1998 and 1999, respectively.