Serge Brouyère

University of Liège | ulg · Department of Architecture, Geology, Environment & Constructions (ArGEnCo)

Many studies have highlighted that climate change will have a negative impact on groundwater in many areas. However, in previous studies, the estimation of uncertainty around projections was very limited. In this study, the impact of climate change on groundwater resources is estimated for the Geer basin using a surface-subsurface integrated model....

The spatial distribution and temporal dynamics of a benzene plume in an alluvial aquifer strongly affected by river fluctuations was studied. Benzene concentrations, aquifer geochemistry datasets, past river morphology, and benzene degradation rates estimated in situ using stable carbon isotope enrichment were analyzed in concert with aquifer heter...

In the context of the Water Framework Directive (EP and CEU, 2000), management plans have to be set up to monitor and to maintain water quality in groundwater bodies in the EU. In heavily industrialized and urbanized areas, the cumulative effect of multiple contaminant sources is likely and has to be evaluated. In order to propose adequate measures...

Regional degradation of groundwater resources by nitrate has become one of the main challenges for water managers worldwide. Regulations have been defined to reverse observed nitrate trends in groundwater bodies, such as the Water Framework Directive and the Groundwater Daughter Directive in the European Union. In such a context, one of the main ch...

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 conditio...

Considering the importance of characterizing groundwater flow for assessing recharge and contaminant transport, this study investigates the potential of two field methods to estimate groundwater fluxes in consolidated aquifers. To accomplish this, both the finite volume point dilution method (FVPDM) test and active distributed temperature sensing (...

The Finite Volume Point Dilution Method (FVPDM) is a single-well tracer experiment which has been successfully used in many hydrogeological contexts to quantify groundwater fluxes. During continuous injection of tracer into a well, the tracer concentration evolution measured within the tested well directly depends on the groundwater flow crossing t...

In 2020, the European Union has established a recast of the 1998 EU Directive on the quality of water intended for human consumption, hereafter called Drinking Water Directive – DWD. One of the most significant innovative point in this recast is the introduction of an innovative “complete risk-based approach to water safety, covering the whole supp...

Groundwater catchment located in peri-urban areas may be impacted by many pollutants coming from different types of point or diffuse sources such as accidental spills, continuous hidden leaks in drainage networks, old landfills, treated/untreated wastewater and watercourses. In the scope of the CASPER project, a new methodological approach has been...

The subsurface provides multiple resources of which the exploitation has a lasting impact on future potential provision. Establishing sustainability in terms of fundamental principles, and fitting these principles into a practical framework, is an ongoing endeavour focused mainly on surface activities. The principles of ecological economics lead to...

The chalk porosity plays a decisive role in the transport of solutes and heat in saturated chalk. From a geological point of view, there are at least two types of porosities: the porosity of pores corresponding to the micro-spaces between the fossil coccoliths that form the chalk matrix, and the porosity due to the micro- and macro-fractures (i.e.,...

Spring water geochemistry is applied here to evaluate the geothermal potential in Rhenohercynian fold and thrust belt around the deepest borehole in Belgium (Havelange borehole: 5648 m MD). Fifty springs and (few) wells around Havelange borehole were chosen according to a multicriteria approach including the hydrothermal source of “Chaudfontaine” (...

In Southern Belgium, 23% of abstracted groundwater volumes are from chalk aquifers which represent strategic resources for the region. Due to their specific nature, these chalk aquifers often exhibit singular behaviour and require specific analysis. The quantitative evolution of these groundwater resources is analysed for the Mons Basin and Hesbaye...

In a Belgian chalky aquifer, groundwater quality has been locally affected by a mixture of Chlorinated Aliphatic Hydrocarbons (CAHs) dominated by 1,1,1-trichloroethene (1,1,1-TCA). The first results showed that the latter undergoes abiotic degradation by hydrolysis and dehydrohalogenation in the saturated zone. The released acids (hydrochloric and...

In central Benin, fluoride concentrations in groundwater generally exceed the national and WHO guideline values (1.5 mg/L) and are locally above 7 mg/L (max. 7.19 mg/L). In this area, aquifers are found in a Precambrian bedrock made of migmatitic gneiss and granites. Recent hydrogeochemical studies have shown that the occurrence of fluoride in grou...

Study region: North of Sahara, Algeria. Study focus: The effects of water/rock interactions and hydrodynamic conditions on the characteristics of groundwater in the Continental Intercalaire aquifer (CI) are demonstrated using hydrochemical and isotopic data from the Mzab Ridge. New hydrological insights: The results confirm that CI groundwater in...

Aquifers under agricultural areas are considered to be an indirect source of nitrous oxide emission (N2O) to the atmosphere, which is the greenhouse gas (GHGs) characterized with the highest global warning potential and acts as a stratospheric ozone depletion agent. Previous investigations performed in the Cretaceous Hesbaye chalk aquifer in Easter...

An extensive survey of groundwater quality was performed at the regional scale in peri-urban and industrial contexts of the Walloon Region (Belgium). To this end, 243 sampling locations from 8 areas located in different geological contexts and different peri-urban areas of the region were sampled outside pollution hotspots related to contaminated s...

The Senegal River Delta located in north-western Senegal is a strategic region for the development of irrigated rice cultivation for achieving rice self-sufficiency. The presence of a shallow salty water table is often considered as a brake to the development of irrigation, by causing salinization of the soil, although the mechanisms of operation a...

Through the practice of irrigation, surface water reservoirs (SWRs) contribute to the socioeconomic development and food production activities of populations in Sub-Saharan Africa (SSA). However, they tend to dry up prematurely. One solution to circumvent these irrigation water shortages is to ensure their conjunctive use with groundwater. The obje...

Permafrost thaw is a complex process resulting from interactions between the atmosphere, soil, water and vegetation. Although advective heat transport by groundwater at depth likely plays a significant role in permafrost dynamics at many sites, there is lack of direct measurements of groundwater flow patterns and fluxes in such cold-region environm...

Exposure from groundwater contamination to aquatic receptors residing in receiving surface water is dependent upon the rate of contaminated groundwater discharge. Characterization of groundwater fluxes is challenging, especially in coastal environments where tidal fluctuations result in transient groundwater flows towards these receptors. This can...

An abandoned industrial site in Belgium, located in the catchment of a chalk aquifer mainly used for drinking water, has been investigated for groundwater pollution due to a mixture of chlorinated solvents with mainly 1,1,1-trichloroethane (1,1,1-TCA) at high concentrations. The observed elevated groundwater mineralization was partly explained by c...

In the context of aridity of the Mzab valley, groundwater presents the only available source for water supplies. The Mzab water management system that is an ancestral floodwater harvesting system aims to valorise the limited amounts of floodwater on irrigation of palm groves and recharge of the shallow aquifer. The Touzouz infiltration basin (TIB)...

Groundwater vulnerability maps can be combined with pollution hazards to assess risks of groundwater pollution. However, groundwater vulnerability maps are generally difficult to interpret because they differ according to the factors considered and the way they are combined. Here, starting from process-based concepts and criteria, a robust definiti...

At an abandoned industrial site in Belgium, groundwater quality in a chalky aquifer had been impacted by a mixture of chlorinated aliphatic hydrocarbons inducing a significant change in hydrochemistry that is not fully understood. In previous investigations close to this site within the contaminant plume, an important increase of Ca, HCO3 and Cl w...

In this study the variability of greenhouse gases (GHGs) concentrations along lateral and vertical dimensions of the chalk aquifer located in the eastern part of Belgium was examined in order to understand its dependence on hydrogeological and hydrogeochemical conditions. Groundwater samples from 29 wells/piezometers were analyzed for concentration...

High concentrations of fluoride (up to 7 mg/L) are observed in the hard crystalline aquifers in the central part of Benin (Department of Collines) while the WHO recommended standard is 1.5 mg/L. The drinking of water with high fluoride contents affects human heath as dental fluorosis which already occurs frequently in the region. The hydrogeochemic...

AkvaGIS is a novel, free and open source module included in the FREEWAT plugin for QGIS that supplies astandardized and easy-to-use workflow for the storage, management, visualization and analysis of hydro-chemical and hydrogeological data. The main application is devised to simplify the characterization ofgroundwater bodies for the purpose of buil...

The northern Sahara contains vast aquifer systems, including the Intercalary Continental Shelf (ICS) which is the main water reserve for the regions of the Great Western Erg and the Mzab Ridge (Algerian northern Sahara). In order to identify the different processes controlling the acquisition and modification of the ICS water mineralization, differ...

Base flow estimation is of overwhelming importance in hydrological modeling and water resource management. One of the widely used techniques to derive base flow from measured streamflow is the recursive digital filter (RDF). Yet its application still raises methodological issues related to the determination of its parameters. In this study, we prop...

This study investigates the occurrence of greenhouse gases (GHGs) and the role of groundwater as an indirect pathway of GHG emissions into surface waters in a gaining stretch of the Triffoy River agricultural catchment (Belgium). To this end, nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) concentrations, the stable isotopes of nitrate,...

Classic estimates of groundwater fluxes are usually based on the application of Darcy's law, which can lead to large imprecisions in transient groundwater flow cases. There is a need for direct, in situ measurement techniques able to monitor time-variable groundwater fluxes. The investigation presented here demonstrates that the Finite Volume Point...

In the central part of the semi-arid Dargol Basin of southwestern Niger, most of the groundwater resource is contained in the fractured aquifers of the Precambrian basement. The groundwater resource is poorly characterized and this study is the first attempt to better describe the recharge mechanisms and hydrogeochemical behaviour of the aquifers....

Underground pumped storage hydropower (UPSH) using abandoned mines is an alternative system to manage electricity production in flat regions. Water from an underground reservoir is pumped to a surface reservoir to store electricity in the form of potential energy. Later, water is discharged through turbines into the underground reservoir to produce...

This work reviews applications of stable isotope analysis to the studies of transport and transformation of N species in groundwater under agricultural areas. It summarizes evidence regarding factors affecting the isotopic composition of NO3−, NH4 + and N2O in subsurface, and discusses the use of 11B, 18O, 13C, 34S, 87Sr/86Sr isotopes to support th...

This work aims to (1) identify the most conductive conditions for the generation of greenhouse gases (GHGs) in groundwater (e.g., hydrogeological contexts and geochemical processes) and (2) evaluate the indirect emissions of GHGs from groundwater at a regional scale in Wallonia (Belgium). To this end, nitrous oxide (N2O), methane (CH4) and carbon d...

We report a data-set of CO2, CH4, and N2O concentrations in the surface waters of the Meuse river network in Belgium, obtained during four surveys covering 50 stations (summer 2013 and late winter 2013, 2014 and 2015), from yearly cycles in four rivers of variable size and catchment land cover, and from 111 groundwater samples. Surface waters of th...

In the central part of Benin (Western Africa), high fluoride \(\left( {{\text{F}}^{ - } } \right)\) contents have been reported in groundwater from Precambrian crystalline bedrock aquifer which is the main source of drinking water. The hydrogeochemical mechanisms leading to such elevated fluoride concentrations are usually not fully understood. In...

Underground Pumped Storage Hydropower (UPSH) is an alternative to manage the electricity production in flat regions. UPSH plants consist of two reservoirs of which at least one is underground. For this last reservoir, abandoned mines could be considered. UPSH related activities may induce hydrochemical variations, such as the increase of the oxygen...

Study region: Senegal River Delta. Study focus: The Senegal River Delta is a strategic region for the development of irrigated agriculture. Despite a Sahelian climatic context, the management of the river with dams ensures water availability throughout the year. With the intensification of agriculture, degradation of cultivated soils is observed, m...

Les eaux souterraines constituent la principale ressource en eau pour les zones arides. Le Sahara algérien est quasi-totalement dépendant de l’aquifère du Continentale Intercalaire (CI) pour s’approvisionner en eau tant pour utilisation domestique qu’agricole et industrielle. Ces dernières décennies, cet aquifère a subit une croissante pression sui...

Factors governing spatial and temporal patterns of pesticide compounds (pesticides and metabolites) concentrations in chalk aquifers remain unclear due to complex flow processes and multiple sources. To uncover which factors govern pesticide compound concentrations in a chalk aquifer, we develop a methodology based on time series analyses, uni- and...

Core Ideas Time‐lapse ERT imaging was combined with VMS data in a brownfield. The setup monitored an infiltrated saline tracer across the vadose zone. The spatial distribution of the tracer was monitored with geophysics. Flow mechanisms inferred from VMS data improved subsoil characterization. Both technologies combined can improve site conceptual...

In the actual evolving energy context, characterized by an increasing part of intermittent renewable sources, the development of energy storage technologies are required, such as pumped storage hydroelectricity (PSH). While new sites for conventional PSH plants are getting scarce, it is proposed to use abandoned underground mines as lower reservoir...

Geothermal field characterization and heat tracer experiments often rely on scarce temperature data collected in boreholes. Electrical resistivity tomography (ERT) and distributed temperature sensing (DTS) have the potential to provide spatial information on temperature changes in the subsurface. In this contribution, we show how DTS and ERT have b...

Among remediation methods for contaminated sites, in-situ bioremediation appears as a competitive treatment in terms of cost and environmental concerns. However, the efficiency of such a technique strongly depends on the environment affected and is still difficult to predict a priori unless carrying out extensive drilling and sampling, which can be...

Groundwater under industrial sites is characterised by heterogeneous chemical mixtures, making it difficult to assess the fate and transport of individual contaminants. Quantifying the in-situ biological removal (attenuation) of nitrogen (N) is particularly difficult due to its reactivity and ubiquity. Here a multi-isotope approach is developed to...

Using heat as an active tracer for aquifer characterization is a topic of increasing interest. In this study, we investigate the potential of using heat tracer tests for characterization of a shallow alluvial aquifer. A thermal tracer test was conducted in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simulta...

Using heat as an active tracer for aquifer characterization is a topic of increasing interest. In this study, we investigate the potential of using heat tracer tests for characterization of a shallow alluvial aquifer. A thermal tracer test was conducted in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simulta...

Water flow and solute transport through a fractured vadose zone underneath an industrial contaminated site in Belgium were studied with a new methodological concept. The Vadose Zone Experimental Setup (VZES) combines a vadose zone monitoring system (VMS) with cross-borehole geophysics. The VMS provides continuous chemical and hydraulic information...

Compound-specific isotope analysis (CSIA) is a powerful tool to track contaminant fate in groundwater. However, the application of CSIA to chlorinated ethanes has received little attention so far. These compounds are toxic and prevalent groundwater contaminants of environmental concern. The high susceptibility of chlorinated ethanes like 1,1,1-tric...

Measurement of groundwater fluxes is the basis of all hydrogeological study, from hydraulic characterization to the most advanced reactive transport modeling. Usual groundwater flux estimation with Darcy's law may lead to cumulated errors on spatial variability, especially in fractured aquifers where local direct measurement of groundwater fluxes b...

A general physically based method is presented to assess the vulnerability of groundwater to external pressures by numerical simulation of groundwater flow. The concept of groundwater vulnerability assessment considered here is based on the calculation of sensitivity coefficients for a user-defined groundwater state for which we propose several phy...

Geothermal energy systems, closed or open, are increasingly considered for heating and/or cooling buildings. The efficiency of such systems depends on the thermal properties of the subsurface. Therefore, feasibility and impact studies performed prior to their installation should include a field characterization of thermal properties and a heat tran...

The management of urban rivers which drain contaminated groundwater is suffering from high uncertainties regarding reliable quantification of groundwater fluxes. Independent techniques are combined for estimating these fluxes towards the Zenne River, Belgium. Measured hydraulic gradients, temperature gradients in conjunction with a 1D-heat and flui...

The Diass horst aquifer system located 50 km east of Dakar (Senegal) is exploited in two main aquifers covered by a sandy superficial aquifer: the confined/unconfined Palaeocene karstic limestone and the confined Maastrichtian sandstone aquifer underneath. This system has experienced intensive groundwater abstraction during the last 50 years to sup...

Models are the only tools capable of predicting the evolution of groundwater systems at a regional scale, by taking into account a large amount of information. This study presents the association of a water balance model (WetSpass) with a groundwater flow and solute transport model (SUFT3D, saturated and unsaturated flow and transport in 3D) in ord...

The growing demand for renewable energy leads to an increase in the development of geothermal energy projects and heat has become a common tracer in hydrology and hydrogeology. Designing geothermal systems requires a multidisciplinary approach including geological and hydrogeological aspects. In this context, electrical resistivity tomography (ERT)...

Thermal tracing experiments are becoming common in hydrogeology to estimate parameters governing heat transport processes and to study geothermal reservoirs. Electrical resistivity tomography (ERT) has proven its ability to monitor salt tracer tests, but few studies have investigated its performances in thermal tracing experiments. In this study, w...

The coarse resolution of climate models creates the need for future scenarios which are downscaled to an appropriate spatial scale. Considerable effort has been devoted to the development of downscaling methods, but a number of important issues remain to meet users' needs. These include the assessment of uncertainty for future scenarios, and the pr...

In Europe, 30% of groundwater bodies are considered to be at risk of not achieving the Water Framework Directive (WFD) 'good status' objective by 2015, and 45% are in doubt of doing so. Diffuse agricultural pollution is one of the main pressures affecting groundwater bodies. To tackle this problem, the WFD requires Member States to design and imple...

Several studies have highlighted the potential negative impact of climate change on groundwater reserves, but additional work is required to help water managers plan for future changes. In particular, existing studies provide projections for a stationary climate representative of the end of the century, although information is demanded for the near...

ERT and SP investigations were conducted in carbonate rocks of the Dinant Synclinorium (Walloon Region of Belgium) to find suitable locations for new water wells in zones with little hydrogeological data. Since boreholes information needed to be representati