Loading...
6 results
Search Results
Now showing 1 - 6 of 6
- The water crisis in southern Portugal: how did we get there and how should we solve itPublication . Nunes, Luís; Monteiro, José Paulo; Cunha, M. C.; Vieira, J.; Lucas, H.; Ribeiro, L.; Brebbia, C. A.; Conti, M. E.; Tiezzi, E.Until very recently, the public water supply in the Algarve region was almost entirely supported by groundwater wells. However, in the last years of the 20th Century, the Portuguese government defined a scheme for the public water supply sector entirely based on surface water from large dams, in order to guarantee the public water supply. The efforts to abandon groundwater as a source for public supply started in 1998, after a large investment in new infrastructures and rehabilitation of some existing ones. However, the practical implementation of this water supply scheme showed that an integrated resource management is needed in order to implement a more economical and reliable solution. The present paper describes the historical background and the evolution of water use in recent decades until the present time in the Algarve, and a proposal for restructuring the management of the water supplies based on the development of a decision support system within an integrated water resources management scheme.
- Recursos hídricosPublication . Cunha, Luís V.; Ribeiro, Luís; Oliveira, Ricardo P.; Nascimento, João; Monteiro, José Paulo; Dill, Amélia Maria Mello de Carvalho; Nunes, L.O Projecto "Climate Change in Portugal. Scenarios, Impacts and Adaptation Measures" (SIAM) iniciou-se em meados de 1999, com o financiamento da Fundação Calouste Gulbenkian e da Fundação para a Ciência e a Tecnologia. O Projecto SIAM teve como objectivo a realização da primeira avaliação integrada dos impactos e medidas de adaptação às alterações climáticas em Portugal Continental no século XXI. Os estudos realizados basearam-se em cenários do clima futuro obtidos a partir de modelos de circulação geral da atmosfera e incidiram sobre um conjunto de sectores sócio-económicos e sistemas biofísicos designadamente: recursos hídricos, zonas costeiras, agricultura, saúde humana, energia, florestas e biodiversidade e pescas. Foi também realizada uma análise sociológica sobre a problemática das alterações climáticas em Portugal. As principais conclusões obtidas no Projecto SIAM foram publicadas num Sumário Executivo e Conclusões, lançado em Outubro de 2001, editado em português e em inglês.A segunda fase do Projecto SIAM (SIAM II) iniciou-se em Janeiro de 2002. Esta segunda fase focou-se no estudo de caso do Estuário do Sado, tendo os estudos sido alargados às Regiões Autónomas da Madeira e dos Açores. O SIAM II incluiu ainda uma componente de Outreach que teve como objectivo a divulgação dos resultados obtidos no SIAM I aos diversos agentes interessados, obtendo ainda inputs para o SIAM II, através da organização de reuniões nas quais participaram as equipas dos sectores considerados relevantes para a região escolhida e os respectivos agentes interessados. O SIAM II foi financiado pelo Instituto do Ambiente, do Ministério das Cidades, do Ordenamento do Território e Ambiente.
- The water crisis in southern Portugal: how did we get there and how should we solve itPublication . Nunes, Luís; Monteiro, José Paulo; Cunha, Maria da Conceição; Vieira, João; Lucas, Helena; Ribeiro, LuísUntil very recently, public water supply in the Algarve region was almost entirely supported by groundwater wells. However, in the last years of the XX Century, the Portuguese central administration defined a scheme for the public water supply sector entirely based in surface water from large dams, in order to guarantee the public water supply. The efforts to abandon groundwater as a source for public supply started in 1998, after a large investment in new infrastructures and rehabilitation of other ones. However, the practical implementation of this water supply scheme showed that an integrated resource management is needed in order to implement a more economical and reliable solution. The present paper describes the historical background and the evolution of water use in the last decades until the present time in the Algarve, and a proposal for restructuring the management of the water supplies based in the development of a decision support system in the scope of an integrated water resources management.
- A influência da temperatura na germinação de sementes do endemismo algarvio Tuberaria MajorPublication . Fernandes, Janete; Monteiro, José Paulo; Fernandes, Jacinta; Osório, Júlio; Correia, Maria JoãoAs sementes de Tuberaria major (willk.) P. Silva & Rozeira, um endemismo lusitano com distribuição limitada à região do Algarve, apresentam a testa dura, que é responsável pela dormência primária das mesmas.
- Optimized exploitation of aquifers: application to the Querenca-Silves aquifer systemPublication . Ferreira, J.; Cunha, M. C.; Vieira, J.; Monteiro, José Paulo; Brebbia, C. A.; Popov, V.A great deal of optimization models have been developed to support aquifer planning and management with the goal of arriving at the best decisions in relation to the number and siting of infrastructures to be built and how to operate them. A mixed-integer multi-objective linear model has been taken from the literature to define the best decision for the development of the aquifer of Querenca-Silves (Portugal). It identifies efficient solutions for the location and design of pumping stations and their catchment area to supply a given number of demand centers, without disregarding the effect of groundwater management on the piezometric surface of aquifers and the many facets of groundwater management. The multi-objective model includes two objectives: (1) the minimization of aggregate water elevation height, and (2) the minimization of aggregate water transport length, weighted by the flows conveyed from the facilities to the centers. The effect of groundwater extraction on the piezometric surface of the aquifer is modelled with a response matrix method, with the establishment of maximum drawdown to prevent over-exploitation.
- Screening of sustainable groundwater sources for integration into a regional drought-prone water supply systemPublication . Stigter, T. Y.; Monteiro, José Paulo; Nunes, L.; Vieira, João; Cunha, Maria da Conceição; Ribeiro, Luís; Nascimento, João; Lucas, HelenaThis paper reports on the qualitative and quantitative screening of groundwater sources for integration into the public water supply system of the Algarve, Portugal. The results are employed in a decision support system currently under development for an integrated water resources management scheme in the region. Such a scheme is crucial for several reasons, including the extreme seasonal and annual variations in rainfall, the effect of climate change on more frequent and long-lasting droughts, the continuously increasing water demand and the high risk of a single-source water supply policy. The latter was revealed during the severe drought of 2004 and 2005, when surface reservoirs were depleted and the regional water demand could not be met, despite the drilling of emergency wells. For screening and selection, quantitative criteria are based on aquifer properties and well yields, whereas qualitative criteria are defined by water quality indices. These reflect the well’s degree of violation of drinking water standards for different sets of variables, including toxicity parameters, nitrate and chloride, iron and manganese and microbiological parameters. Results indicate the current availability of at least 1100 l s−1 of high quality groundwater (55% of the regional demand), requiring only disinfection (900 l s−1) or basic treatment, prior to human consumption. These groundwater withdrawals are sustainable when compared to mean annual recharge, considering that at least 40% is preserved for ecological demands. A more accurate and comprehensive analysis of sustainability is performed with the help of steady-state and transient groundwater flow simulations, which account for aquifer geometry, boundary conditions, recharge and discharge rates, pumping activity and season. (tibor.stigter@ist.utl.pt) ality. They permit an advanced analysis of present and future scenarios and show that increasing water demands and decreasing rainfall will make the water supply system extremely vulnerable, with a high risk of groundwater salinization and ecosystem degradation.