Integrative Groundwater Studies in a Small-Scale Urban Area: Case Study from the Municipality of Penafiel (NW Portugal)
Liliana Freitas,
Helder I. Chaminé,
Maria José Afonso,
Helen Meerkhan,
Tiago Abreu,
José Filinto Trigo,
Alcides J. S. C. Pereira
Affiliations
Liliana Freitas
L<span style="font-variant: small-caps">abcarga</span>—Laboratory of Cartography and Applied Geology, Department of Geotechnical Engineering, School of Engineering (ISEP), Polytechnic of Porto, 4200-072 Porto, Portugal
Helder I. Chaminé
L<span style="font-variant: small-caps">abcarga</span>—Laboratory of Cartography and Applied Geology, Department of Geotechnical Engineering, School of Engineering (ISEP), Polytechnic of Porto, 4200-072 Porto, Portugal
Maria José Afonso
L<span style="font-variant: small-caps">abcarga</span>—Laboratory of Cartography and Applied Geology, Department of Geotechnical Engineering, School of Engineering (ISEP), Polytechnic of Porto, 4200-072 Porto, Portugal
Helen Meerkhan
L<span style="font-variant: small-caps">abcarga</span>—Laboratory of Cartography and Applied Geology, Department of Geotechnical Engineering, School of Engineering (ISEP), Polytechnic of Porto, 4200-072 Porto, Portugal
Tiago Abreu
Department of Civil Engineering, School of Engineering (ISEP), Polytechnic of Porto, 4200-072 Porto, Portugal
José Filinto Trigo
L<span style="font-variant: small-caps">abcarga</span>—Laboratory of Cartography and Applied Geology, Department of Geotechnical Engineering, School of Engineering (ISEP), Polytechnic of Porto, 4200-072 Porto, Portugal
Alcides J. S. C. Pereira
CITEUC, Department of Earth Sciences, Faculty of Sciences and Technology, University of Coimbra, 3030-790 Coimbra, Portugal
The occurrence of groundwater in urban hard rock areas is mostly controlled by secondary permeability caused by the fracturing degree and weathering grade. Vulnerability GIS-mapping, monitoring, and infiltration/recharge of water resources, and the delineation of the environmental protective background are key issues in evaluating, planning, managing, and decision-making for urban water systems. A small-scale urban area in Penafiel City was used as a case study. Historical and current scenarios were compared using hydrogeological GIS-based modelling. Water sources and potential contamination sources were mapped around the study area. Groundwater is mainly acidic, with a low mineralization and a Cl-Na to Cl-SO4-Na or Cl-Ca to Cl-SO4-Ca hydrogeochemical facies. Considering potential contamination sources, the moderate and the moderate-high classes dominate the area. The combined approach of the vulnerability indexes suggests that most of the area has a low to moderate vulnerability to contamination. The Infiltration Potential Index in urban areas (IPI-urban) indicates the prevalence of a low to moderate infiltration. Groundwater recharge evaluation indicates values < 2.3 mm/year and <60 mm/year for summer and winter scenarios, respectively. Finally, the investigation addresses insights for decision-makers for the appropriate planning and sustainable management of groundwater resources in small-scale urban areas.
