|
|
|
|
|
|
|
|
HYH-02 Groundwater resources and management
|
|
|
|
Identification and management of strategic groundwater bodies for emergency situations in Portugal (Images)
|
|
|
|
MariaTeresa Condesso De Melo, Instituto Superior Técnico, Lisbon, Portugal (Portugal)
Judite Fernandes, LNEG, National Laboratory for Energy and Geology (Portugal)
Carla Midões, LNEG, National Laboratory for Energy and Geology (Portugal)
Helena Amaral, EAWAG, Department of Water Resources and Drinking Wate (Switzerland)
Carlos Costa Almeida, LNEG, National Laboratory for Energy and Geology (Portugal)
Manuel Augusto Marques da Silva, GeoBioTec, University of Aveiro (Portugal)
João José Lopo Mendonça, Centro de Geociências, FCUL (Portugal)
|
|
|
|
Climate change (floods and droughts), geological hazards, such as earthquakes and landslides, and contamination episodes related to nuclear and industrial accidents, may cause serious disruption in the coverage and quality of public water supply. Furthermore, the superficial water reservoirs are frequently plagued by quality problems, in European countries with warm temperatures, for instance algal blooms related to eutrophication processes, or by the presence of anoxic chemical species formed in depth under low redox potential conditions that may limit the water for human consumption. Man made impacts such as diffuse contamination from agriculture, especially with nitrates, also affect superficial water reservoirs and groundwater with short residence time. Consequently the identification, characterization and evaluation of groundwater bodies that could be used as strategic reserves in case of extreme hydrologic events, catastrophes, terrorist attacks and conflicts are a present concern for the water authorities in Portugal and the main aim of the IMAGES project.
Ten aquifer systems located in littoral centre region of Portugal have been object of study. The groundwater bodies suitable for such purpose should be characterized by water of good quality, long residence time and low vulnerability. As the groundwater turn over time of these aquifers is very long, their management must be carefully designed and requires the understanding of past hydrological changes to predict the impacts of future climatic and environmental change on water resources.
The available data of preliminary surveys suggest that some of these aquifers may contain significant reserves of fresh good quality water with long residence times. A first evaluation of the water age performed by tritium, CFC and SF6 analyses, distinguished modern from old waters in these aquifers. The groundwater quality was assessed with a detailed hydrogeochemical characterization. 14C analyses were used to identify groundwaters recharged under palaeoconditions.
|
|
|
|
|
|
|
|
|
