1. a Laboratory of Hydrology, Faculty of Pharmacy , University of Oporto , Rua Aníbal Cunha, 164, 4050 Porto, Portugal
2. b Laboratory of Hydrology, Faculty of Pharmacy , University of Oporto , Rua Aníbal Cunha, 164, 4050 Porto, Portugal
3. c IAREN-Water Institute of the Northern Region , Rua Aníbal Cunha, 164, 4050 Porto, Portugal