Iniciar sessão

Navegar para Cima
Instituto de Investigação
em Vulcanologia e Avaliação de Riscos
Última hora:

Artigos em revistas ► internacionais com arbitragem


Referência Bibliográfica

FERNANDES, A.L., CRUZ, J.V., FIGUEIRA, C., PRADA, S. (2020) -  Groundwater chemistry in Madeira Island (Portugal): main processes and contribution to the hydrogeological conceptual model. Environmental Earth Sciences 79:413, doi: 10.1007/s12665-020-09151-8.


​Groundwater resources are the main water supply source of Madeira Island, thus the characterization of the main hydro-geological mechanisms is vital for their sustainable management. Through the present study, a large hydrochemical dataset was analyzed by traditional and PCA analysis in light of the conceptual hydrogeological model of the island. Groundwater is mainly characterized by being low mineralized (mean EC = 128.6 µS/cm), cold (mean temperature = 13.4 °C) and slightly acidic (mean pH = 6.7). Springs draining local and small perched aquifer have low solute content and local flow path, while drilled wells, tapped in the basal aquifer near the coast, are more mineralized. Groundwaters are of the Na–HCO3, Mg–HCO3, Ca–HCO3 and Na–Cl types. The latter is found in some springs and in a few drilled wells. The hydrogeochemical
and principal component analysis identify silicate weathering process as the most important factor involved in groundwater mineralization, as also CO2 dissolution and seawater spraying. Based on the 3H levels, most groundwaters have a significant component of modern recharge. Springs correspond to young waters, whilst waters in tunnels/galleries and drilled wells are mixtures of modern and submodern waters. The lower 3H concentration in these waters indicates longer residence time in the aquifers than spring water with higher levels and recent recharge. In general, flow paths are local and shallow. The interpretation of the chemical data in conjunction with 3H and δ18O data is in line with the conceptual model of Madeira Island proposed by Prada et al. (Comun Inst Geol Min 90:125–142, 2003; J Hydrol 536:409–425, 2016).