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- Delineating Groundwater Vulnerability and Protection Zone Mapping in Fractured Rock Masses: Focus on the DISCO IndexPublication . Meerkhan, Helen; Teixeira, José; Marques, Jorge Espinha; Afonso, Maria José; Chaminé, Helder I.Hard-rock catchments are considered to be source of valuable water resources for water supply to inhabitants and ecosystems. The present work aims to develop a groundwater vulnerability approach in the Caldas da Cavaca hydromineral system (Aguiar da Beira, Central Portugal) in order to improve the hydrogeological conceptual site model. Different types of information were overlaid, generating several thematic maps to achieve an integrated framework of key sectors in the study site. Thus, a multi-technical approach was used, encompassing field and laboratory techniques, whereby different types of data were collected from fields such as geology, hydrogeology, applied geomorphology and geophysics and hydrogeomechanics, with the fundamental aim of applying the so-called DISCO index method. All of these techniques were successfully performed and an intrinsic groundwater vulnerability to contamination assessment, based on the multicriteria methodology of GOD-S, DRASTIC-Fm, SINTACS, SI and DISCO indexes, was delineated. Geographic Information Systems (GIS) provided the basis on which to organize and integrate the databases and to produce all the thematic maps. This multi-technical approach highlights the importance of groundwater vulnerability to contamination mapping as a tool to support hydrogeological conceptualization, contributing to improving the decision-making process regarding water resources management and sustainability.
- Environmental Groundwater Vulnerability Assessment in Urban Water MinesPublication . Afonso, Maria José; Freitas, Liliana; Pereira, Alcides; Neves, Luís; Guimarães, Laura; Guilhermino, Lúcia; Mayer, Bernhard; Rocha, Fernando; Marques, José Manuel; Chaminé, Helder I.A multidisciplinary approach was developed to estimate urban groundwater vulnerability to contamination combining hydrogeology, hydrogeochemistry, subterranean hydrogeotechnics, groundwater ecotoxicology and isotope tracers. Paranhos and Salgueiros spring waters in Porto City were used as a case study. Historical and current vulnerability scenarios were compared using hydrogeological GIS-based modelling. Potential contamination sources were mapped around the spring galleries. Most of these were point sources and their potential contamination load was moderate. The ecotoxicological assessment indicated a low acute toxicity potential. Groundwater radionuclides appeared to be mainly controlled by geological factors and biomineralisation. Vulnerability maps suggest that most of the area has a moderate to low vulnerability to contamination. However, some surface sources such as sewage systems cause contamination and contribute to increased vulnerability. This integrated approach was demonstrated to be adequate for a better knowledge of urban hydrogeological processes and their dynamics, and highlighted the importance of a vulnerability assessment in urban areas.
- From engineering geosciences mapping towards sustainable urban planningPublication . Chaminé, Helder I.; Teixeira, José; Freitas, Liliana; Pires, Ana; Silva, Rui S.; Pinho, Telma; Monteiro, Rosália; Costa, Ana Lúcia; Abreu, Tiago; Trigo, José Filinto; Afonso, Maria José; Carvalho, José MartinsMaps are of key topical importance in urban geoscience and engineering practice, mainly in field data synthesis and communication related to a number of fields, such as geomatic techniques, applied geology and geomorphology, engineering geology, soil and rock geotechnics, slope geotechnics, subsurface site geotechnical investigations, urban hydrology, hydraulics and sanitation, coastal zones management, urban geoarcheology and heritage, planning and land use. The value of preparing engineering geoscience maps and plans specificallyfor urban engineering purposes are still a challenging task, particularly to end-users and planners. Nowadays, the application of Geographic Information Systems to geosciences and engineering has become more common. This paper emphasises the importance of an accurate ground field survey and inventory at several scales, GIS mapping and databases, and integrated multidisciplinary urban studies as useful tools to support a sustainable land use planning. Some selected sites are highlighted to demonstrate the importance of urban mapping for land use planning. Thus, in this study the significance of a smart urban geoscience approach is stressed.
- From historical hydrogeological inventory through GIS mapping to problem solving in urban groundwater systemsPublication . Chaminé, Helder I.; Afonso, Maria José; Freitas, LilianaWater resources have had a huge impact on the socioeconomic sustainability and development of urban areas. The close relationship between water and human society has been important throughout the history of civilization. The water supply for early urban settlements included mainly the use of river canals, rainwater-harvesting systems, wells, aqueducts and underground cisterns. The industrialisation period in Europe promoted an increase in population and expansion of urban areas. Furthermore, several epidemics devastated European urban areas in the period between the18th and 19th centuries. Unhygienic conditions caused by polluted water, human and animal waste and excreta were among the main causes. This study discusses the importance of historical hydrogeological inventories in a large urban area, such as Porto city (NW Portugal), to better comprehend the evolution of urban water supply systems. In that approach urban geosciences need to advance towards a smart urban geoscience concept.
- Geodynamic evolution of the SW Europe VariscidesPublication . Ribeiro, António; Munhá, José; Dias, Rui; Mateus, António; Pereira, Eurico; Ribeiro, Luísa; Fonseca, Paulo; Araújo, Alexandre; Oliveira, Tomás; Romão, José; Chaminé, Helder I.; Coke, Carlos; Pedro, JorgeThe early evolution of SW Europe Variscides started by opening of the Rheic ocean at 500 Ma, splitting Avalonia from Armorica/Iberia. Subduction on the SE side of Rheic generated the Paleotethys back-arc basin (430–390 Ma, splitting Armorica from Iberia), with development of Porto-Tomar-Ferreira do Alentejo (PTFA) dextral transform defining the boundary between continental Armorica and Finisterra microplate to the W. Obduction of Paleotethys was followed by Armorica/Iberia collision and emplacement of NW Iberian Allochthonous Units at 390–370 Ma, whereas toward the west of PTFA, there was antithetic ophiolite obduction (Beja-Acebuches and Rheic ophiolites plus Finisterra continental slices) on top of Ossa-Morena Zone, with simultaneous development of eclogites and orogenic magmatism under a flake– double wedge tectonic regime. Continued convergence (<370 Ma) proceeded by intracontinental deformation, with progressive tightening of the Ibero-Armorican Arc through dextral transpression on the Cantabrian Indentor, from Iberia to Armorica. The proposed model is discussed at the light of the driving mechanism of ‘‘soft plate tectonics.’’
- Integrative Groundwater Studies in a Small-Scale Urban Area: Case Study from the Municipality of Penafiel (NW Portugal)Publication . Freitas, Liliana; Chaminé, Helder I.; Afonso, Maria José; Meerkhan, Helen; Abreu, Tiago; Trigo, José Filinto; Pereira, Alcides J. S. C.The occurrence of groundwater in urban hard rock areas is mostly controlled by secondary permeability caused by the fracturing degree and weathering grade. Vulnerability GIS-mapping, monitoring, and infiltration/recharge of water resources, and the delineation of the environmental protective background are key issues in evaluating, planning, managing, and decision-making for urban water systems. A small-scale urban area in Penafiel City was used as a case study. Historical and current scenarios were compared using hydrogeological GIS-based modelling. Water sources and potential contamination sources were mapped around the study area. Groundwater is mainly acidic, with a low mineralization and a Cl-Na to Cl-SO4-Na or Cl-Ca to Cl-SO4-Ca hydrogeochemical facies. Considering potential contamination sources, the moderate and the moderate-high classes dominate the area. The combined approach of the vulnerability indexes suggests that most of the area has a low to moderate vulnerability to contamination. The Infiltration Potential Index in urban areas (IPI-urban) indicates the prevalence of a low to moderate infiltration. Groundwater recharge evaluation indicates values < 2.3 mm/year and <60 mm/year for summer and winter scenarios, respectively. Finally, the investigation addresses insights for decision-makers for the appropriate planning and sustainable management of groundwater resources in small-scale urban areas.
- On a dialogue between hard-rock aquifer mapping and hydrogeological conceptual models: insights into groundwater explorationPublication . Chaminé, Helder I.; Carvalho, José Martins; Afonso, Maria José; Teixeira, José; Freitas, LilianaGroundwater is a dynamic and renewable resource, but in hard-rock terrains its availability is rather limited compared to other types of aquifer formations. Groundwater systems require a comprehensive understanding of geology, morphotectonics and hydrology, which are controlled by ground characteristics like weathering grade, fracturing degree, permeability, slope, drainage pattern and density, land cover, and climate. GIS-based integrative cartography provides an accurate way to improve knowledge on water circulation models and on the global functioning of aquifer systems. The groundwater conceptual model based in Earth systems has proven its value in water resource studies. This approach highlights the importance of groundwater exploration mapping as a useful tool to support hydrogeological conceptualisation of fractured hard-rock terrains, contributing to the sustainability of water resources.
- Role of hydrogeological mapping in groundwater practice: back to basicsPublication . Chaminé, Helder I.; Carvalho, José Martins; Teixeira, José; Freitas, LilianaMaps are of key importance in groundwater professional practice and hydrogeology research, mainly in field data synthesis and communication related to a number of fields: regional hydrogeology, exploration hydrogeology, groundwater engineering, hydrogeophysics, hydrogeomorphology, urban groundwater, military geology/engineering, thermal water resources, planning, management and decision making on the water resources. This paper highlights the importance and necessity of accurate ground field surveys at several scales, water resources inventory and an integrated groundwater mapping as useful tools to support hydrogeological conceptualisation. Selected sites are highlighted to demonstrate the importance of groundwater mapping for assessment of water resources. Conceptualisation of groundwater systems must be grounded on Earth-based models and mathematical modelling to outline predicting scenarios. Thus, going back to basics is important to create a reliable conceptualization on groundwater systems established on cartographic reasoning.
- Site appraisal in fractured rock media: coupling engineering geological mapping and geotechnical modellingPublication . Chaminé, Helder I.; Afonso, Maria José; Trigo, José Filinto; Freitas, Liliana; Ramos, Luís; Carvalho, José MartinsGeotechnical surveys are based on collecting data from fieldwork and are a key element of rock-mass quality assessment in rock engineering. The lessons learned in several engineering projects underline the value of the accuracy of the basic geological and geotechnical data information related to the rock masses description and evaluation. An evaluation based on engineering geosciences, hydraulic and geotechnical features of rock masses involves combining parameters to derive quantitative geomechanical classifications for engineering design. In the present work, two selected sites are highlighted to demonstrate the importance of GIS mapping and models. Mapping and quantifying the on-site measurements’ information content and building a geo-database is vital for decision-making processes and risk assessment on sustainable engineering design with nature and hazards.
- Urban Groundwater Processes and Anthropogenic Interactions (Porto Region, NW Portugal)Publication . Afonso, Maria José; Freitas, Liliana; Marques, José Manuel; Carreira, Paula M.; Pereira, Alcides J.S.C.; Rocha, Fernando; Chaminé, Helder I.Groundwater in fissured rocks is one of the most important reserves of available fresh water, and urbanization applies an extremely complex pressure which puts this natural resource at risk. Two-thirds of Portugal is composed of fissured aquifers. In this context, the Porto urban region is the second biggest metropolitan area in mainland Portugal. In this study, a multidisciplinary approach was developed, using hydrogeological GIS-based mapping and modeling, combining hydrogeochemical, isotopic, and hydrodynamical data. In addition, an urban infiltration potential index (IPI-Urban) was outlined with the combination of several thematic layers. Hydrogeochemical signatures are mainly Cl-Na to Cl-SO4-Na, being dependent on the geographic proximity of this region to the ocean, and on anthropogenic and agricultural contamination processes, namely fertilizers, sewage, as well as animal and human wastes. Isotopic signatures characterize a meteoric origin for groundwater, with shallow flow paths and short residence times. Pumping tests revealed a semi- to confined system, with low long-term well capacities (<1 L/s), low transmissivities (<4 m2/day), and low storage coefficients (<10−2). The IPI-Urban index showed a low groundwater infiltration potential, which was enhanced by urban hydraulic and sanitation features. This study assessed the major hydrogeological processes and their dynamics, therefore, contributing to a better knowledge of sustainable urban groundwater systems in fractured media