References of "Brouyère, Serge"
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See detailLarge scale surface – subsurface hydrological model to assess climate change impacts on groundwater reserves
Goderniaux, Pascal ULg; Brouyère, Serge ULg; Fowler, Hayley J. et al

in Journal of Hydrology (2009), 373

Estimating the impacts of climate change on groundwater represents one of the most difficult challenges faced by water resources specialists. One difficulty is that simplifying the representation of the ... [more ▼]

Estimating the impacts of climate change on groundwater represents one of the most difficult challenges faced by water resources specialists. One difficulty is that simplifying the representation of the hydrological system often leads to discrepancies in projections. This study provides an improved methodology for the estimation of the impacts of climate change on groundwater reserves, where a physically-based surface – subsurface flow model is combined with advanced climate change scenarios for the Geer basin (465 km²), Belgium. Coupled surface–subsurface flow is simulated with the finite element model HydroGeoSphere. The simultaneous solution of surface and subsurface flow equations in HydroGeoSphere, as well as the internal calculation of the actual evapotranspiration as a function of the soil moisture at each node of the defined evaporative zone, improve the representation of interdependent processes like recharge, which is crucial in the context of climate change. More simple models or externally coupled models do not provide the same level of realism. Fully integrated surface – subsurface flow models have recently gained attention, but have not been used in the context of climate change impact studies. Climate change simulations were obtained from 6 regional climate model (RCM) scenarios assuming the SRES A2 emission (medium-high) scenario. These RCM scenarios were downscaled using a quantile mapping bias-correction technique that, rather than applying a correction only to the mean, forces the probability distributions of the control simulations of daily temperature and precipitation to match the observed distributions. The same corrections are then applied to RCM scenarios for the future. Climate change scenarios predict hotter and drier summer and warmer and wetter winters. The combined use of an integrated surface – subsurface modelling approach, a spatial representation of the evapotranspiration processes and sophisticated climate change scenarios improves the model realism and projections of climate change impacts on groundwater reserves. For the climatic scenarios considered, the integrated flow simulations show that significant decreases are expected in the groundwater levels (up to 8 meters) and in the surface water flow rates (between 9% and 33%) by 2080. [less ▲]

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See detailBenzene dispersion and natural attenuation in an alluvial aquifer with strong interactions with surface water
Batlle-Aguilar, Jordi; Brouyère, Serge ULg; Dassargues, Alain ULg et al

in Journal of Hydrology (2009)

Field and laboratory investigations have been conducted at a former coke plant, in order to assess pollutant attenuation in a contaminated alluvial aquifer, discharging to an adjacent river. Various ... [more ▼]

Field and laboratory investigations have been conducted at a former coke plant, in order to assess pollutant attenuation in a contaminated alluvial aquifer, discharging to an adjacent river. Various organic (BTEX, PAHs, mineral oils) and inorganic (As, Zn, Cd) compounds were found in the aquifer in concentrations exceeding regulatory values. Due to redox conditions of the aquifer, heavy metals were almost immobile, thus not posing a major risk of dispersion off-site the brownfield. Field and laboratory investigations demonstrated that benzene, among organic pollutants, presented the major worry for off-site dispersion, mainly due to its mobility and high concentration, i.e. up to 750 mg L 1 in the source zone. However, benzene could never be detected near the river which is about 160 m downgradient the main source. Redox conditions together with benzene concentrations determined in the aquifer have suggested that degradation mainly occurred within 100 m distance from the contaminant source under anoxic conditions, and most probably with sulphate as main oxidant. A numerical groundwater flow and transport model, calibrated under transient conditions, was used to simulate benzene attenuation in the alluvial aquifer towards the Meuse River. The mean benzene degradation rate used in the model was quantified in situ along the groundwater flow path using compound-specific carbon isotope analysis (CSIA). The results of the solute transport simulations confirmed that benzene concentrations decreased almost five orders of magnitude 70 m downgradient the source. Simulated concentrations have been found to be below the detection limit in the zone adjacent to the river and consistent with the absence of benzene in downgradient piezometers located close to the river reported in groundwater sampling campaigns. In a transient model scenario including groundwater–surface water dynamics, benzene concentrations were observed to be inversely correlated to the river water levels, leading to the hypothesis that benzene dispersion is mainly controlled by natural attenuation. [less ▲]

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See detailMobility, turnover and storage of pollutants in soils, sediments and waters: achievements and results of the EU project AquaTerra. A review
Barth, J. A. C.; Grathwohl, P.; Fowler, H. J. et al

in Agronomy for Sustainable Development (2009), 29(1), 161-173

AquaTerra is one of the first environmental projects within the 6th Framework program by the European Commission. It began in June 2004 with a multidisciplinary team of 45 partner organizations from 13 EU ... [more ▼]

AquaTerra is one of the first environmental projects within the 6th Framework program by the European Commission. It began in June 2004 with a multidisciplinary team of 45 partner organizations from 13 EU countries, Switzerland, Serbia, Romania and Montenegro. Results from sampling and modeling in 4 large river basins (Ebro, Danube, Elbe and Meuse) and one catchment of the Brévilles Spring in France led to new evaluations of diffuse and hotspot input of persistent organic and metal pollutants including dynamics of pesticides and polycyclic aromatic hydrocarbons, as well as metal turnover and accumulation. While degradation of selected organic compounds could be demonstrated under controlled conditions in the laboratory, turnover of most persistent pollutants in the field seems to range from decades to centuries. First investigations of long-term cumulative and degradation effects, particularly in the context of climate change, have shown that it is also necessary to consider the predictions of more than one climate model when trying to assess future impacts. This is largely controlled by uncertainties in climate model responses. It is becoming evident, however, that changes to the climate will have important impacts on the diffusion and degradation of pollutants in space and time that are just at the start of their exploration. [less ▲]

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See detailAssessing and aggregating trends in groundwater bodies. Examples of the FP VI Aquaterra-project
Broers, Hans-peter; Visser, Ate; Brouyère, Serge ULg et al

in EU Groundwater Policy Development - Good Status Objectives and Integrated management planning (2008, November)

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See detailDraft overview paper on trend analysis in groundwater summarizing the main results of TREND2 in relation to the new Groundwater Directive
Broers, H.P.; Visser, A.; Bierkens, M.F.P. et al

Report (2008)

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See detailDL 45 : Application and validation of the general methodology and concept of groundwater vulnerability assessment at regional scale on the Israeli coastal aquifer
Beaujean, Jean ULg; Lemieux, Jean-Michel; Brouyère, Serge ULg

Report (2008)

This deliverable consists in applying the concepts and methodologies developed in Deliverable D43 and D44 to synthetic and real case studies. Our researches have focused on the generalized groundwater ... [more ▼]

This deliverable consists in applying the concepts and methodologies developed in Deliverable D43 and D44 to synthetic and real case studies. Our researches have focused on the generalized groundwater vulnerability assessment methodology, and more precisely on evaluating, under the framework of physically-based indicators, the groundwater sensitivity/vulnerability to stress factor considering artificial recharge as a potential response to the degradation of the groundwater resource. In the context, different approaches have been identified in the literature and implemented in appropriate modelling tools (i.e. HydroGeoSphere) for calculating the various sensitivity/vulnerability coefficients. These approaches are the influence coefficient method, the sensitivity equation method and the adjoint operator method. The two first methods show relevant results on both the considered synthetic case studies that relate groundwater vulnerability to (1) quantity issues and (2) to sea water intrusion. They illustrate the way of applying the methodology to “real case studies”.These first applications should be the object of more complex but strongly related case studies. [less ▲]

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See detailA new tracer technique for monitoring groundwater fluxes : the finite volume point dilution method
Brouyère, Serge ULg; Batlle-Aguilar, Jordi; Goderniaux, Pascal ULg et al

Conference (2008, June 06)

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See detailDevelopment of the Geer basin Hydrological model for climatic scenarios and first results about impacts evaluation
Goderniaux, Pascal ULg; Brouyère, Serge ULg; Orban, Philippe ULg et al

Report (2008)

A surface – subsurface flow numerical model of the Geer basin (465 km²) has been implemented to assess the possible impacts of climate change on the groundwater resources. This model is physically-based ... [more ▼]

A surface – subsurface flow numerical model of the Geer basin (465 km²) has been implemented to assess the possible impacts of climate change on the groundwater resources. This model is physically-based, spatially-distributed and it integrates totally the groundwater and surface water. Simulations were performed using 6 climate change scenarios generated by the University of Newcastle-Upon-Tyne. These scenarios simulate changes in the amplitude, but also in the frequency and persistence of some meteorological events. First results show that, according the implemented flow model and the used climatic scenarios, significant decreases are expected in the groundwater levels (up to 12 meters) and in the surface water flow rates (reduction between 16% and 32%) [less ▲]

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See detailGroundwater flow and transport model for the Flémalle cokery site
Batlle-Aguilar, Jordi; Brouyère, Serge ULg

Report (2008)

This deliverable describes the groundwater flow and transport model performed for the Flémalle test site. Calibration of the groundwater model has been done using both, zoning and pilot points approaches ... [more ▼]

This deliverable describes the groundwater flow and transport model performed for the Flémalle test site. Calibration of the groundwater model has been done using both, zoning and pilot points approaches, while model transport calibration has been performed using tracer tests carried out. Different scenarios of pollutant concentration and degradation constant rates have been simulated. Results point out that biodegradation is likely to occur, as evidenced by former studies within BGC in the scope of the AquaTerra project. [less ▲]

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See detailDL 44 : Methodology and setup of the adopted groundwater vulnerability assessment method
Beaujean, Jean ULg; Wojda, Piotr; Gardin, Nicolas et al

Report (2008)

The objectives of this deliverable DL44 are to finalize the description of the global groundwater vulnerability assessment methodology, in particular : (1) to propose an extension of the concept of ... [more ▼]

The objectives of this deliverable DL44 are to finalize the description of the global groundwater vulnerability assessment methodology, in particular : (1) to propose an extension of the concept of sensitivity coefficient to vulnerability coefficient by introducing a ratio (distance to damage ratio) that reflects the “distance” between the current state of degradation of the water resource system and the “damaged state”,(2) To describe the methodology proposed to combine, through aggregation of spatiallydistributed indicators and multi criteria analysis, the different vulnerability coefficientsinto a single indicator of groundwater vulnerability for decision making, (3) To go further into the analysis and discussion of several key theoretical “case studies” for illustrating the way to setup the full methodology, from the DPSIR analysis to the expression of sensitivity and vulnerability coefficients. [less ▲]

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See detailEtude de tendance dans les hauteurs piézométriques mesurées au piézomètre de Viemme
Orban, Philippe ULg; Batlle-Aguilar, Jordi; Brouyère, Serge ULg et al

Report (2008)

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See detailReport on the development of the Geer Hydrological model. Final results about climate change impacts evaluation.
Goderniaux, Pascal ULg; Brouyère, Serge ULg; Orban, Philippe ULg et al

Report (2008)

In the framework of Workpackage BASIN R3 Meuse, the Hydrology Group of the University of Liège (Belgium) has developed a hydrological model of the Geer sub-catchment, in order to assess climate change ... [more ▼]

In the framework of Workpackage BASIN R3 Meuse, the Hydrology Group of the University of Liège (Belgium) has developed a hydrological model of the Geer sub-catchment, in order to assess climate change impacts on groundwater reserves. The water resource Systems Research Laboratory of the Newcastle University has produced the climate change scenarios applied on the hydrological model. This report describes the methodology used, the implementation of the hydrological model, the climate change scenarios and the results of the study. [less ▲]

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See detailInterpretation of a tracer test at Brévilles after 2 years of monitoring
Goderniaux, Pascal ULg; Gutierrez, Alexis; Brouyère, Serge ULg

Report (2008)

To understand and predict the behaviour and transfer of diffuse contamination, a small catchment is intensively studied in the vicinity of Paris. A multi tracer test involving a new technique, the FVPDM ... [more ▼]

To understand and predict the behaviour and transfer of diffuse contamination, a small catchment is intensively studied in the vicinity of Paris. A multi tracer test involving a new technique, the FVPDM method (Finite Volume Point Dilution Method - Brouyère et al., 2008) has been performed in natural flow conditions. Injections of four different tracers (uranine, sulforhodamine B, lithium chloride and potassium iodide) took place in four piezometers involving different areas of the aquifer and different depth. This tracer test follows a former test briefly described. A particularly long monitoring (Nov-2005 to Feb-2008) demonstrates the existence of several transport velocities within the sandy layer, which seems linked to the decrease of hydraulic conductivity with depth. Absence of recovery of two tracers confirms the results of the former test and identifies spatial heterogeneities probably due to the geological structure. The new insight and parameter quantification brought by interpretation of these tests contributes to a better characterization of the saturated zone and shall be exploited through modelling for transport predictions of pesticides. [less ▲]

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See detailA New Tracer Technique for Monitoring Groundwater Fluxes: The Finite Volume Point Dilution Method
Brouyère, Serge ULg; Batlle-Aguilar, Jordi; Goderniaux, Pascal ULg et al

in Journal of Contaminant Hydrology (2008), 95(3-4), 121-40

Quantification of pollutant mass fluxes is essential for assessing the impact of contaminated sites on their surrounding environment, particularly on adjacent surface water bodies. In this context, it is ... [more ▼]

Quantification of pollutant mass fluxes is essential for assessing the impact of contaminated sites on their surrounding environment, particularly on adjacent surface water bodies. In this context, it is essential to quantify but also to be able to monitor the variations with time of Darcy fluxes in relation with changes in hydrogeological conditions and groundwater - surface water interactions. A new tracer technique is proposed that generalizes the single-well point dilution method to the case of finite volumes of tracer fluid and water flush. It is called the Finite Volume Point Dilution Method (FVPDM). It is based on an analytical solution derived from a mathematical model proposed recently to accurately model tracer injection into a well. Using a non-dimensional formulation of the analytical solution, a sensitivity analysis is performed on the concentration evolution in the injection well, according to tracer injection conditions and well-aquifer interactions. Based on this analysis, optimised field techniques and interpretation methods are proposed. The new tracer technique is easier to implement in the field than the classical point dilution method while it further allows monitoring temporal changes of the magnitude of estimated Darcy fluxes, which is not the case for the former technique. The new technique was applied to two experimental sites with contrasting objectives, geological and hydrogeological conditions, and field equipment facilities. In both cases, field tracer concentrations monitored in the injection wells were used to fit the calculated modelled concentrations by adjusting the apparent Darcy flux crossing the well screens. Modelling results are very satisfactory and indicate that the methodology is efficient and accurate, with a wide range of potential applications in different environments and experimental conditions, including the monitoring with time of changes in Darcy fluxes. [less ▲]

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