Water in Celtic Countries: Quantity, Quality and Climate Variability (Proceedings of the Fourth InterCeltic Colloquium on Hydrology and Management of Water Resources, Guimarães, Portugal, July 2005). IAHS Publ. 310, 2007, 37-48.
Impacts of climate change
on water resources: a case-study for Portugal
LUIS VEIGA DA CUNHA1, RODRIGO PROENÇA DE OLIVEIRA2,1, JOÃO NASCIMENTO3 & LUIS RIBEIRO3
1 Department of Environmental Sciences and Engineering, Universidade Nova
de Lisboa, Lisbon, Portugal
lvdacunha@mail.telepac.pt
2 Department
of Environmental Sciences and Engineering, Universidade Nova de Lisboa, Lisbon,
Portugal and Chiron, Information Systems, Lisbon, Portugal
3 Instituto
Superior Técnico, Universidade Técnica de Lisboa, Lisbon, Portugal
Abstract The
paper briefly analyses the impacts of climate change on water resources and
identifies, in general terms, the specific impacts related to different
hydrological variables and different characteristics of the water systems. A
case study of the impacts of climate change on Portuguese water resources
developed within the SIAM project, is introduced. The climate scenarios
considered, corresponding to selected climate models, show a small increase of
annual precipitation for the northern region of Portugal and a decrease for the
central and southern regions. The models also predict an increase of seasonal
asymmetry with relevant decreases in summer precipitation. The annual average
temperature appears to increase, particularly in southern Portugal. These
climatic scenarios lead to a probable trend towards a concentration of river
runoff in winter and an increase in the current seasonal asymmetry of water
availability in Portugal. It also appears that the concentration of rainfall in
winter and the estimated general increase in the frequency of heavy
precipitation events is likely to augment the magnitude and frequency of
flooding, particularly in the northern part of the country. The predicted
decrease of river flow in southern Portugal, during the next century,
associated with an increase in the spatial and temporal asymmetry of water
resources distribution, may have very serious consequences and be a cause of
major concern. It may, in fact, have strong implications for the water resources
management strategies and policies to be designed for Portugal. Finally, how
the consideration of climate change on water resources should influence the
future planning and management of water resources, both in general terms and in
the specific case of Portugal, is analysed. In particular, the joint study of
climate change impacts on the water resources shared by Spain and Portugal is
proposed as a major focus for scientific and technological co-operation of the
two countries of the Iberian Peninsula.
Key
words adaptation
measures; climate change; impacts; water resources