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See detailHydrogeological data requirements for assessment of natural attenuation
Haerens, Bruno; Dassargues, Alain ULg

in Proceedings of the National Colloquium CBGI-BCGI ‘Réhabilitation des zones polluées, inventaire, gestion et assainissement / Herinrichting van verontreinigdde zones, inventaris, beheer en sanering (2002)

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See detailHydrogeological investigations at the Membach station, Belgium, and application to correct long periodic gravity variations
Van Camp, Michel; Vanclooster, Marnik; Crommen, O. et al

in Journal of Geophysical Research (2006), 111(B10),

A comprehensive hydrogeological investigation regarding the influence of variations in local and regional water mass on superconducting gravity measurements is presented for observations taken near the ... [more ▼]

A comprehensive hydrogeological investigation regarding the influence of variations in local and regional water mass on superconducting gravity measurements is presented for observations taken near the geodynamic station of Membach, Belgium. Applying a regional water storage model, the gravity contribution due to the elastic deformation of the Earth was derived. In addition, the Newtonian gravity effect induced by the local water mass variations was calculated, using soil moisture observations taken at the ground surface (about 48 m above the gravimeters). The computation of the gravimetric effect is based on a digital elevation model with spatially discretized rectangular prisms. The obtained results are compared with the observations of a superconducting gravimeter (SG). We find that the seasonal variations can be reasonably well predicted with the regional water storage model and the local Newtonian effects. Shorter-period effects depend on the local changes in hydrology. This result shows the sensitivity of SG observations to very local water storage changes. [less ▲]

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See detailHydrogeological mapping of the Walloon region (Belgium).
Bouezmarni, Mohamed ULg

in Proceedings of the 5th european congress on regional geoscientific cartography and information systems. (2006)

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See detailHydrogeological modeling of radionuclide transport in heterogeneous low-permeability media: a comparison between Boom Clay and Ieper Clay
Huysmans, Marijke; Dassargues, Alain ULg

in Soares, A.; Pereira, M. J.; Dimitrakopoulos, R. (Eds.) GeoENV VI: Geostatistics for Environmental Applications (2006)

Deep low-permeability clay layers are considered as possible suitable environments for disposal of high-level radioactive waste. In Belgium, the Boom Clay is the reference host formation and the Ieper ... [more ▼]

Deep low-permeability clay layers are considered as possible suitable environments for disposal of high-level radioactive waste. In Belgium, the Boom Clay is the reference host formation and the Ieper Clay an alternative host formation for research and safety and feasibility assessment of deep disposal of nuclear waste. In this study, two hydrogeological models are built to calculate the radionuclide fluxes that would migrate from a potential repository through these two clay formations. Transport parameters heterogeneity is incorporated in the models using stochastic sequential simulation of hydraulic conductivity, diffusion coefficient and diffusion accessible porosity, using primary information and several types of secondary information, i.e. resistivity, gamma ray and grain size. The calculated radionuclide fluxes in the two clay formations are compared. Results show that in the Ieper Clay larger differences between the fluxes through the lower and the upper clay boundary occur, larger total output radionuclide amounts are calculated, and a larger effect of parameter heterogeneity on the calculated fluxes is observed, compared to the Boom Clay. [less ▲]

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See detailHydrogeological modeling of radionuclide transport in low permeability media: a comparison between Boom Clay and Ypresian Clay
Huysmans, Marijke; Dassargues, Alain ULg

in Environmental Geology (2006), 50(1), 122-131

Deep low-permeability clay layers are considered as suitable environments for disposal of high-level radioactive waste. In Belgium, the Boom Clay is the reference host formation and the Ypresian Clay an ... [more ▼]

Deep low-permeability clay layers are considered as suitable environments for disposal of high-level radioactive waste. In Belgium, the Boom Clay is the reference host formation and the Ypresian Clay an alternative host formation for research and safety and feasibility assessment of deep disposal of nuclear waste. In this study, two hydrogeological models are built to calculate the radionuclide fluxes that would migrate from a potential repository through these two clay formations. Transport parameter heterogeneity is incorporated in the models using geostatistical co-simulations of hydraulic conductivity, diffusion coefficient and diffusion accessible porosity. The calculated radionuclide fluxes in the two clay formations are compared. The results show that in the Ypresian Clay larger differences between the fluxes through the lower and the upper clay boundary occur, larger total output radionuclide amounts are calculated and a larger effect of parameter heterogeneity on the calculated fluxes is observed, compared to the Boom Clay. [less ▲]

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See detailHydrogeological processes in fractured and porous media: insights from geophysical case studies
Robert, Tanguy ULg; Hermans, Thomas ULg; Nguyen, Frédéric ULg

Conference (2013, January 18)

This presentation focuses on geophysical case studies with the aim to highlight the possibilities to study and monitor hydrogeological processes in the subsurface, including transport processes in ... [more ▼]

This presentation focuses on geophysical case studies with the aim to highlight the possibilities to study and monitor hydrogeological processes in the subsurface, including transport processes in fractured or in porous media. The presentation emphasizes two geoelectrical methods, namely electrical resistivity tomography (ERT) which images the electrical resistivity distribution of the subsurface and self-potential (SP) whose measured signal is directly sensitive to groundwater fluxes. The first case study concerns the geophysical identification and characterization of large hydraulically-active fractured areas in calcareous synclines and in particular the assessment of the joint use of ERT and SP to set up new piezometers in fractured limestone. This assessment shows that piezometers drilled inside less resistive areas and/or in negative SP anomalies presented high hydraulic capacities. Inversely, piezometers drilled inside more resistive zones and/or outside an SP anomaly presented low hydraulic capacities. The SP anomaly related to preferential flow in fractures was thus demonstrated for the first time. All these fractures information, obtained with geophysics, improved the conceptualization and calibration of the groundwater flow model of the calcareous valley. A seasonal monitoring of SP signals proved to be a successful methodology to better understand the hydrodynamics of calcareous aquifers and in particular to follow the seasonal drawdown of the water table in the calcareous valley. Different methodologies to delineate the main groundwater flow direction were also tested. The latter can be achieved for example by drawing an SP map showing the main hydraulic gradients or by monitoring a salt tracer test with ERT to highlight preferential flow in fractures. The second case study concerns the ERT monitoring of a shallow geothermal test conducted in a porous medium (sand). The main objective of this study was to derive temperature from a series of electrical resistivity images since the electrical resistivity is directly sensitive to temperature changes. This field work demonstrates that surface electric resistivity tomography can monitor heat injection and storage experiments in shallow aquifers providing a number of practical applications, such as the monitoring or the design of shallow geothermal systems or the use of heated water to replace salt water in tracer tests. Through these two different case studies, this presentation also emphasizes in a practical way on the importance of data inversion and image appraisal since these issues are crucial to quantitatively study hydrogeological processes. [less ▲]

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See detailHydrogeological study and modelling to implement a groundwater restoration plan near leaking soda industry landfills
Brouyère, Serge ULg; Dassargues, Alain ULg; Michiels, Thierry

in 2nd Int. Symp. on Environmental Contamination, Budapest (1994)

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See detailHydrogeological study by geophysical prospection in Florennes
Dassargues, Alain ULg; Hallet, Vincent; Monjoie, Albéric

Report (1986)

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See detailHydrogeological study of Somes-Szamos transboundary alluvial aquifer
Drobot, Radu; Szucs, Peter; Brouyère, Serge ULg et al

in Ganoulis, Jacques; Aureli, Alice; Fried, Jean (Eds.) Transboundary Water Resources Management: A Multidisciplinary Approach (2011)

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See detailHydrogeological study of Somes-Szamos transboundary alluvial aquifer
Dassargues, Alain ULg; Drobot, Radu; Lenart, Laszlo et al

in Technical/Scientific Issues of Transboudary Water Management: Experience from around the world (2008)

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See detailHydrogeological survey at the Diegem IBM site – First stage and geophysical investigation
Biver, Pierre; Dassargues, Alain ULg; Monjoie, Albéric

Report (1988)

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See detailHydrogeological survey in Diegem (IBM) – Stage II – Drilling and pumping tests
Biver, Pierre; Dassargues, Alain ULg; Monjoie, Albéric

Report (1989)

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See detailHydrogéologie du bassin de la Semois. Quelques résultats des études financées par la Région wallonne.
Debbaut, Vincent ULg

in Tribune de l'Eau (La) (1989), 42(538), 32-35

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See detailHydrogéologie du bassin du Samson
Gesels, Julie ULg; Goderniaux, Pascal ULg; Jamin, Pierre ULg et al

in Michel, Georges; Thys, Georges; De Broyer, Claude (Eds.) Atlas du Karst Wallon. Bassins du Bocq et du Samson (2011)

Ce chapitre décrit l'hydrogéologie du bassin du Samsonvdans la partie "articles thématiques" de l'Atlas du karst consacré aux bassins du Bocq et du Samson. Après une description générale, la nature et les ... [more ▼]

Ce chapitre décrit l'hydrogéologie du bassin du Samsonvdans la partie "articles thématiques" de l'Atlas du karst consacré aux bassins du Bocq et du Samson. Après une description générale, la nature et les potentialités aquifères du bassin du Samson sont abordées : les unités hydrogéologiques sont décrites, des aspects quantitatifs et des bilans hydrogéologiques sont détaillés et des aspects qualitatifs sont développés. [less ▲]

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See detailHydrogéologie et grands travaux du Génie Civil - Hydrogeologie en grote civieltechnische werken
Schroeder, Christian; Huysmans, Marijke; Dassargues, Alain ULg

in Dassargues, Alain; Walraevens, Kristine (Eds.) Watervoerende lagen & grondwater in België - Aquifères & eaux souterraines en Belgique (2014)

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See detailA hydrographic and bio-chemical climatology of the Mediterranean and the Black Sea: a technical note on the use of coastal data
Rixen, M.; Beckers, Jean-Marie ULg; Maillard, C. et al

in Bollettino di Geofisica Teorica ed Applicata (2005), 46

The aim of the MEDAR/MEDATLAS II project was to archive and rescue multidisciplinary in-situ hydrographic and bio-chemical data of the Mediterranean and the Black Sea through a wide cooperation of ... [more ▼]

The aim of the MEDAR/MEDATLAS II project was to archive and rescue multidisciplinary in-situ hydrographic and bio-chemical data of the Mediterranean and the Black Sea through a wide cooperation of countries and to produce a climatological atlas of 12 core parameters, which include temperature and salinity, dissolved oxygen, hydrogen sulphur, alkalinity, phosphate, ammonium, nitrite, nitrate, silicate, chlorophyll and pH. Gridded fields have been computed using the Variational Inverse Model and calibrated by Generalized Cross Validation, by making usual assumptions on the statistical distribution of data and errors. They have been produced for both the Mediterranean and the Black Sea and several additional sub-basins including the Alboran Sea, the Balearic Sea, the Gulf of Lyons and the Ligurian Sea, the Sicily Strait, the Adriatic Sea, the Aegean Sea, the Marmara Sea and the Danube shelf area at climatic, seasonal and monthly scale when relevant. Inter-annual and decadal variability of T/S for both basins have been computed as well. The resulting atlas is made available, free of charge, at "http://modb.oce.ulg.ac.be/Medar" and on CD-Rom. We discuss here some technical issues relating to the use of coastal data in the objective analysis and provide a few examples of features appearing in the climatology. We finally suggest further possible improvements to the analysis method. [less ▲]

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See detailA hydrographic and biochemical climatology of the Mediterranean and the Black Sea: some statistical pitfalls
Rixen, Michel; Beckers, Jean-Marie ULg; Maillard, Catherine

in Vandenberghe, E.; Brown, M.; Costello, M.J (Eds.) et al IOC Workshop Report 188 (2004)

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