BIBLIOS

Document type
Academic documents

Document subtype
Master's dissertation

Title
Impacto das Alterações Climáticas na qualidade das águas subterrâneas de aquíferos carbonatados em Portugal.

Participants in the publication
Oliveira, Joana Margarida dos Santos (Author)
Silva, Maria Catarina Rosalino da (Co-Supervisor)
Dep. Geologia
Dep. Geologia
IDL
Ribeiro, Luís Filipe Tavares (Supervisor)
INSTITUTO SUPERIOR TÉCNICO

Summary
This project intends to be an initial approach to the study of climate change in \ngroundwater sources, specially in kastic aquifers in Portugal, using a qualitative criteria. First, it was made an initial characterization of the saturation state of carbonated \nspecies in all karstic carbonated aquifers of Portugal provided a spatial distribution of the \nsaturation index. Three aquifers were selected for a detailed study of the evolution of \nhydrochemical characteristics relating that evolution to the climate change in order to \nunderstand how temperature and precipitation affect the water quality, adopting a climatic \nevolution model. In all three case studies, Sicó-Alvaiázere, Estremoz-Cano and Querença-Silves \naquifers, a geological, climatic, hydrodynamic and hydrochemical characterization was made in \norder to assess the sensitivity of the aquifer to these factors. It was verified that the waters of the three systems present mainly calcium bicarbonate \nfacies and there were some stations with sodium chloride facies in the extreme SW Querença-\nSilves aquifer that correspond to karst cavities with sea water entry. The evolution of the saturation indexes with increasing temperature and reduced \nprecipitation under climate model HadCM3-A2c was studied and, therefore, initially evaluated \nthe correlation between climate and hydrochemical parameters through linear correlations. By \nstudying the evolution of partial pressure of carbon dioxide (PCO2) due to climate change, it \nwas observed a tendency for increased water solubility, thereby increasing the water dissolution \ncapacity. The quality of drinking and irrigation water was also studied, according to the legislation \nin force, and the SVI quality index (Stigter, et al 2008) was applied to determine the potential \nwater withdrawals for human consumption. The main factors affecting the quality of drinking water are: excessive water hardness, \nnitrate contamination and some microbiological contamination. Considering climate change on \nwater hardness, it was created a timeline to see the evolution of this parameter: it was observed \nan increase of hardness to 2050 and to 2100. The reduction of available surface water, public supply network (based on this resource) \ntends to require the exploitation of groundwater in situations of extreme drought, to ensure the \nsupply of water to the population.


Institution
INSTITUTO SUPERIOR TÉCNICO

Publication Identifiers


Keywords
Aquífero Alterações climáticas índice de saturação dissolução de carbonatos e qualidade da água.