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- Groundwater Favourable Infiltration Zones on Granitic Areas (Central Portugal)Publication . Carvalho, José Martins; Afonso, Maria José; Teixeira, José; Freitas, Liliana; Lopes, Ana Rita; Jesus, Rosário; Batista, Sofia; Carvalho, Rosário; Chaminé, Helder I.The Infiltration Potential Index (IPI) was used at Castelo Novo (Fundão, Central Portugal) to delineate favourable infiltration zones. The Infiltration Potential Index is a valuable tool to include in integrated water resources management in crystalline fractured rocks. An integrated approach combining hydrogeomorphology and GIS was developed applying multiple layers of information (tectonic lineaments, hydrogeological units, slope, drainage, land use, and precipitation). Different ranks were assigned to thematic layers and different weights were given to classes according to their contribution for groundwater using the Analytical Hierarchical Process (AHP) methodology. Almost 80% of the area is covered by slightly to moderately weathered (W1–2–W3) granite, having slopes of 5–15° and 15–25°, tectonic lineaments densities of 6–12 km/km2 and 12–18 km/km2 and drainage densities of 6–9 km/km2 and >9 km/km2. Scrub and/or herbaceous vegetation associations and bare rocks dominate. A moderate to high Infiltration Potential Index (IPI) is dominant in the area.
- Forecasting and Mass Transport Modelling of Nitrates in the Esposende–Vila Do Conde Nitrate Vulnerable Zone (Portugal)Publication . Zeferino, Joel; Carvalho, Maria Rosário; Ferreira, Tânia; Silva, Maria Catarina; Afonso, Maria José; Freitas, Liliana; Lopes, Ana Rita; Jesus, Rosário; Batista, Sofia; Chaminé, Helder I.; Carvalho, José MartinsEsposende–Vila do Conde, a nitrate-vulnerable zone, in the littoral north of Portugal, is contaminated by nitrates of an agricultural origin. Measures have been implemented to reduce that contamination. The effectiveness of the measures was evaluated, predicting the time required for the groundwater body reach the quality standard, i.e., less than 50 mg/L for dissolved nitrates. Two methodologies were used, groundwater flow and nitrates transport modelling, and predictive analysis of time series. The transient simulation of nitrate transport shows that the minimization measures imposed in the NVZ are being effective. However, the persistence of concentrations above 50 mg/L in some areas is notorious even in the next 24 years. The forecasting points out to a recovery period of ten years if current agricultural practices are maintained. The prediction of NO3 concentration based on forecasting methodology may not be applicable in the long run because it is a punctual analysis, not taking into consideration the contaminant dispersion dependent on the aquifer characteristics.