DGEO - Artigo de Conferência em Revista Científica Indexada

URI permanente para esta coleção:

Navegar

Entradas recentes

A mostrar 1 - 6 de 6
  • ItemAcesso Aberto
    Potential Impacts of Land Use Changes on Water Resources in a Tropical Headwater Catchment
    2021-11-16 - Martins, Magda Stella de Melo; Valera, Carlos Alberto; Zanata, Marcelo; Santos, Regina Maria Bessa; Abdala, Vera Lúcia; Pacheco, Fernando António Leal; Fernandes, Luís Filipe Sanches; Pissarra, Teresa Cristina Tarlé
    The main objective of this study was to investigate the relationships between land use and future scenarios of land changes on water runoff and groundwater storage in an Environmental Protection Area (EPAs) watershed. The methodology was based on the application of the Soil and Water Assessment Tool (SWAT) hydrological modelling to investigate flow simulations in current land use and in two future scenarios (forest and pasture). The performance of goodness-of-fit indicators in the calibration (NSE = 0.82, R2 = 0.85, PBIAS = 11.9% and RSR = 0.42) and validation (NSE = 0.70, R 2 = 0.72, PBIAS = −4% and RSR = 0.55) was classified as good and very good, respectively. The model accurately reproduced the inter-annual distribution of rainfall. The spatial distribution of average annual surface flow, lateral flow, and groundwater flow were different between sub-basins. The future scenario on land use change to forest (FRSE) and pasture (PAST) differed during the year, with greater changes on rainy and dry seasons. FRSE increase of 64.5% in area led to decreased surface runoff, total runoff, and soil water; and increased lateral flow, groundwater, and evapotranspiration. The effect of the natural vegetation cover on soil moisture content is still unclear. The hydrological model indicated the main areas of optimal spatial water flow. Considering economic values, those areas should encourage the development of government policies based on incentive platforms that can improve environmental soil and water sustainability by establishing payment for environmental services (PES).
  • ItemAcesso Aberto
    A combined GIS-MCDA approach to prioritize stream water quality interventions, based on the contamination risk and intervention complexity
    2021-07-27 - Fernandes, A. C. P.; Terêncio, D. P. S.; Pacheco, Fernando António Leal; Fernandes, Luis Filipe Sanches
    Water management decisions are complex ever since they are dependent on adopted politics, social objectives, environmental impacts, and economic determinants. To adequately address hydric resources issues, it is crucial to rely on scientific data and models guiding decision-makers. The present study brings a new methodology, consisting of a combined GIS-MCDA, to prioritize catchments that require environmental interventions to improve surface water quality. A Portuguese catchment, Ave River Basin, was selected to test this methodology due to the low water quality. First, it was calculated the contamination risk of each catchment, based on a GISMCDA using point source pressures, landscape metrics, and diffuse emissions as criteria. This analysis was compared to local data of ecological and chemical status through ANOVA and the Tukey test. The results showed the efficiency of the method since the contamination risk was lower for catchments under a good status and higher in catchments with a lower classification. In a second task, it was calculated the intervention complexity using a different GIS-MCDA. For this approach, it was chosen five criteria that condition environmental interventions, population density, slope, percentage of burned areas, Strahler order, and the number of effluent discharge sites. Both multicriteria methods were combined in a graphical analysis to rank the catchments intervention priority, subdividing the prioritization into four categories from 1st to 4th, giving a higher preference for catchments with high contamination risk and low intervention complexity. As a result, catchments with a good status were dominantly placed under low intervention priority, and catchments with a lower ecological status were classified as a high priority, 1st and 2nd. In total, 248 catchments were spatially ranked, which is an essential finding for decision-makers, that are willing to safeguard the catchment water quality.
  • ItemAcesso Aberto
    Reservoir considerations and direct uses of São Pedro do Sul hydromineral and geothermal field, Northern Portugal
    2017 - Gomes, L. M. Ferreira; Trota, A.P. Neves; Oliveira, Alcino De Sousa; Almeida, S. M. Soares
    São Pedro do Sul Hydromineral and Geothermal Field, located in the northern interior zone of Portugal (Lafões zone), has the greatest widespread utilization of geothermal energy in Portugal mainland and is the most important thermal centre from the economical revenues point of view, obtained from direct and indirect utilization of the thermal water, mostly for wellness, health, and leisure of human beings. Recent utilization includes district and greenhouses heating and even cosmetic applications. The Hydromineral Field includes two exploitable zones: the Termas and Vau Poles. The waters are recognised for their mineral and medicinal effects, since the time of the Romans about 2000 years ago and, later on, on the 12th century, by the first King of Portugal, D. Afonso Henriques. The traditional spring and the 500 m well (AC1), located in the Termas Pole, currently supplies artesian hot water flow of about 16.9 L/s with a temperature of 67 ºC. Despite the low flow rate of the actual two exploration wells drilled in the Vau Pole, the geothermal potential is high; a new deep well is planned to be drilled in this zone where is expected to obtain fluid temperature of around 75 ºC. The occurrence of São Pedro do Sul mineral water, included in the sulphurous type waters, are linked to Hercynian granitoids, emplaced between 290 and 321 Myr. There is a close relationship between the placement of the main hot springs and the Verin-Chaves-Penacova fault, namely Verin (Spain), Chaves, Moledo, and S. Pedro do Sul (Portugal) hot springs. Heat flow generated at shallow crustal zones by the radiogenic host mineral of the granitic rocks, added to the deep Earth heat flow, heats the cold water inflow along fractures. Open fracture network along the main faults allows the hot fluids reach the surface, thus giving chance to the occurrence of hot springs and mineralized cold springs. Coupling between fracture opening and density difference between cold water inflow and hot water upflow is assumed to be the main driven factors that explain the occurrence of hot spring in regions with normal to slightly abnormal geothermal gradient. Actual thermal output of the captured fluid in the São Pedro do Sul Hydrothermal area is not fully used, namely in summer times. Thus the main focus for the concessionary includes the saturation of the actual Termas heat power capacity either in the SPA utilization and expansion for newer users in the district heating system. Further studies must be conducted in order to ascertain for possible source deep exploitation to refine quantitatively the São Pedro do Sul reservoir conceptual model in order to make sustainable wise management of this important natural resource, critical for the São Pedro do Sul municipality development and also contributing for the Portuguese sustainable economic growth. In this paper we give new insights for the knowledge of São Pedro do Sul Hydromineral and Geothermal Field, namely the geothermal reservoir, the concession hot water exploitation and future perspectives for upcoming sustainable developments of this valuable natural resource.
  • ItemAcesso Aberto
    Assessment of past and present water quality in closed Mežica Pb-Zn Mine (Slovenia)
    2015 - Doroteja Gosar; Costa, Maria do Rosário Melo; Adelaide Ferreira; S. F. Štrucl
  • ItemAcesso Restrito
    Metais pesados em solos e vegetação espontânea da área de uma mina de chumbo, mina de Barbadalhos, Centro de Portugal
    2014 - Pratas, J.; Favas, P. J. C.; D’Souza, Rohan; Varun, Mayank; Paul, Manoj S.