References of "Vanclooster, Marnik"      in Complete repository Arts & humanities   Archaeology   Art & art history   Classical & oriental studies   History   Languages & linguistics   Literature   Performing arts   Philosophy & ethics   Religion & theology   Multidisciplinary, general & others Business & economic sciences   Accounting & auditing   Production, distribution & supply chain management   Finance   General management & organizational theory   Human resources management   Management information systems   Marketing   Strategy & innovation   Quantitative methods in economics & management   General economics & history of economic thought   International economics   Macroeconomics & monetary economics   Microeconomics   Economic systems & public economics   Social economics   Special economic topics (health, labor, transportation…)   Multidisciplinary, general & others Engineering, computing & technology   Aerospace & aeronautics engineering   Architecture   Chemical engineering   Civil engineering   Computer science   Electrical & electronics engineering   Energy   Geological, petroleum & mining engineering   Materials science & engineering   Mechanical engineering   Multidisciplinary, general & others Human health sciences   Alternative medicine   Anesthesia & intensive care   Cardiovascular & respiratory systems   Dentistry & oral medicine   Dermatology   Endocrinology, metabolism & nutrition   Forensic medicine   Gastroenterology & hepatology   General & internal medicine   Geriatrics   Hematology   Immunology & infectious disease   Laboratory medicine & medical technology   Neurology   Oncology   Ophthalmology   Orthopedics, rehabilitation & sports medicine   Otolaryngology   Pediatrics   Pharmacy, pharmacology & toxicology   Psychiatry   Public health, health care sciences & services   Radiology, nuclear medicine & imaging   Reproductive medicine (gynecology, andrology, obstetrics)   Rheumatology   Surgery   Urology & nephrology   Multidisciplinary, general & others Law, criminology & political science   Civil law   Criminal law & procedure   Criminology   Economic & commercial law   European & international law   Judicial law   Metalaw, Roman law, history of law & comparative law   Political science, public administration & international relations   Public law   Social law   Tax law   Multidisciplinary, general & others Life sciences   Agriculture & agronomy   Anatomy (cytology, histology, embryology...) & physiology   Animal production & animal husbandry   Aquatic sciences & oceanology   Biochemistry, biophysics & molecular biology   Biotechnology   Entomology & pest control   Environmental sciences & ecology   Food science   Genetics & genetic processes   Microbiology   Phytobiology (plant sciences, forestry, mycology...)   Veterinary medicine & animal health   Zoology   Multidisciplinary, general & others Physical, chemical, mathematical & earth Sciences   Chemistry   Earth sciences & physical geography   Mathematics   Physics   Space science, astronomy & astrophysics   Multidisciplinary, general & others Social & behavioral sciences, psychology   Animal psychology, ethology & psychobiology   Anthropology   Communication & mass media   Education & instruction   Human geography & demography   Library & information sciences   Neurosciences & behavior   Regional & inter-regional studies   Social work & social policy   Sociology & social sciences   Social, industrial & organizational psychology   Theoretical & cognitive psychology   Treatment & clinical psychology   Multidisciplinary, general & others     Showing results 1 to 20 of 22 1 2     Direct measurement of evapotranspiration from a forest using a superconducting gravimeterVan Camp, Michel; de Viron, Olivier; Pajot-Métivier, Gwendoline et alin Geophysical Research Letters (2016), 43Evapotranspiration (ET) controls the flux between the land surface and the atmosphere. Assessing the ET ecosystems remains a key challenge in hydrology. We have found that the ET water mass loss can be ... [more ▼]Evapotranspiration (ET) controls the flux between the land surface and the atmosphere. Assessing the ET ecosystems remains a key challenge in hydrology. We have found that the ET water mass loss can be directly inferred from continuous gravity measurements: as water evaporates and transpires from terrestrial ecosystems, the mass distribution of water decreases, changing the gravity field. Using continuous superconducting gravity measurements, we were able to identify daily gravity changes at the level of, or smaller than, 10-9 nms-2 (or 10-10 g) per day. This corresponds to 1.7mmof water over an area of 50 ha. The strength of this method is its ability to enable a direct, traceable and continuous monitoring of actual ET for years at the mesoscale with a high accuracy. [less ▲]Detailed reference viewed: 31 (9 ULg) Hydrology and gravimetry (Assessing groundwater mass balance: Keynote lecture: Hydrogeodesy in Membach and Rochefort)Van Camp, Michel; Vanclooster, Marnik; Watlet, A. et alConference (2015, October 23)For the 10 last years, terrestrial and satellite (GRACE) gravity measurements have reached such a precision that they can be of interest to better monitor underground water masses. First, we show that ... [more ▼]For the 10 last years, terrestrial and satellite (GRACE) gravity measurements have reached such a precision that they can be of interest to better monitor underground water masses. First, we show that terrestrial measurements provide high-precision information about the time evolution of mass changes in the few kilometres square around the gravimeter. Then, examples of the possibilities and limitations of terrestrial measurements are given in Membach, close to Eupen, and in the Rochefort karst system. In Membach, we show that the evapotranspiration can be directly inferred from continuous gravity measurements: as water evaporates and transpires from terrestrial ecosystems, the mass distribution varies through the system, changing its gravity field at the level of, or smaller than 10-10 g per day. This corresponds to 2.0 mm of water over an area of 50 ha. The strength of this method is its ability to ensure a direct, traceable and continuous monitoring of actual ET for years at the mesoscale (~50 ha) with a precision of a few tenths of mm of water. In Rochefort, gravity measurements at the surface and in the cave allows separating the water contained in the unsaturated zone from the saturated one and therefore monitoring groundwater content changes that occur in the unsaturated zone only. [less ▲]Detailed reference viewed: 105 (2 ULg) The use of the Vadose Zone Experimental Setup as an innovative in situ characterization method for the vadose zone: a case study at an industrial contaminated site in BelgiumFernandez de Vera, Natalia ; Beaujean, Jean ; Jamin, Pierre et alConference (2015, September)The development of protection and remediation plans for contaminated soil and groundwater require a detailed understanding of the transport of pollutants in the subsurface. However, such understanding is ... [more ▼]The development of protection and remediation plans for contaminated soil and groundwater require a detailed understanding of the transport of pollutants in the subsurface. However, such understanding is affected by the lack of spatial and temporal coverage provided by the current in situ characterization technologies. A new system has been developed in order to overcome such limitations. The vadose zone experimental setup is a new development combining cross-hole geophysics and the Vadose Zone Monitoring System (VMS). In cross-hole geophysics, an injection of an electrical current using electrodes installed in vertical boreholes is triggered. From measured potential differences, spatial patterns related with subsurface heterogeneities, water content and solute concentrations are inferred. The VMS allows continuous measurements of water content at different depths of the vadose zone, as well as water sampling. The system is formed by a flexible sleeve containing monitoring units along its depth which is installed in a slanted borehole. The system was installed at a former industrial site in Belgium, where soil and groundwater are contaminated with BTEX, PAH, and heavy metals. Two VMS were installed in two slanted boreholes on site, together with four vertical boreholes containing electrodes for geophysical measurements. The site was initially monitored under natural recharge conditions. Water content sensors located along the VMS registered fast wetting and draining reactions to rainfall events followed by the activation of water transport through fractures. Results from soil water samples show continuous evolution of water chemistry with depth, due to disequilibrium between infiltrated water and the hydrochemical conditions in the unsaturated zone. Subsequently, a saline tracer was injected in the surface. The transport of the tracer in the subsurface was monitored via cross-hole and surface geophysics. Results from imaging reflect the evolution of a plume through vertical and lateral transport and dilution. [less ▲]Detailed reference viewed: 130 (15 ULg) Vadose zone characterisation at industrial contaminated sitesFernandez de Vera, Natalia ; Dahan, Ofer; Dassargues, Alain et alin CL:AIRE bulletin (2015)In order to improve risk characterization and remediation measures for soil and groundwater contamination, there is a need to improve in situ vadose zone characterization. However, most available ... [more ▼]In order to improve risk characterization and remediation measures for soil and groundwater contamination, there is a need to improve in situ vadose zone characterization. However, most available technologies have been developed in the context of agricultural soils. Such methodologies are not applicable at industrial sites, where soils and contamination differ in origin and composition. To overcome such difficulties, a vadose zone experiment has been setup at a former industrial site in Belgium. Industrial activities carried out on site left a legacy of soil and groundwater contamination in BTEX, PAH, cyanide and heavy metals. The experiment comprises the combination of two techniques: the Vadose Zone Monitoring System (VMS) and cross-hole geophysics. The VMS allows continuous measurements of water content at different depths of the vadose zone, as well as the possibility of water sampling at different depths. The system is formed by a flexible sleeve containing monitoring units along its depth which is installed in a slanted borehole. The flexible sleeve contains three types of monitoring units in the vadose zone: Time Domain Transmissometry (TDT), which allows water content measurements; Vadose Sampling Ports (VSP), used for collecting water samples coming from the matrix; the Fracture Samplers (FS), which are used for retrieving water samples from the fractures. Cross-hole geophysics techniques consist in the injection of an electrical current using electrodes installed in vertical boreholes. From such injections, spatial patterns related with subsurface heterogeneities, water content and solute concentrations are inferred. Two VMS were installed in two slanted boreholes on site, together with four vertical boreholes containing electrodes for geophysical measurements. The site was monitored under natural recharge conditions. Results show the reaction of the vadose zone to rainfall events, as well as chemical evolution of soil water with depth and rainfall infiltration. [less ▲]Detailed reference viewed: 119 (9 ULg) VADOSE ZONE STUDIES AT AN INDUSTRIAL CONTAMINATED SITE: THE VADOSE ZONE MONITORING SYSTEM AND CROSS-HOLE GEOPHYSICSFernandez de Vera, Natalia ; Beaujean, Jean ; Jamin, Pierre et alConference (2014, September 03)In situ vadose zone characterization is essential to improve risk characterization and remediation measures for soil and groundwater contamination. However, most available technologies have been developed ... [more ▼]In situ vadose zone characterization is essential to improve risk characterization and remediation measures for soil and groundwater contamination. However, most available technologies have been developed in the context of agricultural soils. Most of these methodologies are not applicable at industrial sites, where soils and contamination differ in origin and composition. In addition, they are applicable only in the first meters of soils, leaving deeper vadose zones with lack of information, in particular on field scale heterogeneity. To overcome such difficulties, a vadose zone experiment has been setup at a former industrial site in Belgium. Industrial activities carried out on site left a legacy of soil and groundwater contamination in BTEX, PAH, cyanide and heavy metals. The experiment involves the combination of two techniques: the Vadose Zone Monitoring System (VMS) and cross-hole geophysics. The VMS allows continuous measurements of water content at different depths of the vadose zone (Dahan et al., 2009). In addition, it provides the possibility of pore water sampling at different depths. The system is formed by a flexible sleeve installed in a slanted borehole (Fig. 1) and containing monitoring units along its depth (Fig. 2). The flexible sleeve contains three types of monitoring units in the vadose zone: Time Domain Transmissometry (TDT), which allows water content measurements; Vadose Sampling Ports (VSP), used for collecting water samples coming from the matrix; and the Fracture Samplers (FS), which are used for retrieving water samples from the fractures. Cross-hole electrical tomography measurements are carried providing detailed spatial patterns about electrical properties of the subsurface. Such properties are related with subsurface heterogeneities, water content and solute concentrations. Two VMS were installed on site, together with four vertical boreholes containing electrodes for geophysical measurements. The site has been monitored under natural recharge conditions during the summer, autumn and winter. Results show reactions in the soil at depths up to 6m as a consequence of rainfall infiltration and groundwater level fluctuations. In addition, the chemistry of the soil water changes with depth and water infiltration. Background images obtained from geophysical measurements show a highly conductive subsurface due to the lithologies and the high mineralization of the water in the vadose zone. The combination of cross-hole geophysics with the VMS has provided an effective tool for characterizing the chemistry and the structure of the vadose zone. [less ▲]Detailed reference viewed: 109 (6 ULg) Combined effect of geomorphic and pedogenic processes on the distribution of soil organic carbon quality along an eroding hillslope on loess soilWiaux, François; Cornelis, Jean-Thomas ; Cao, W et alin Geoderma (2014), 216Detailed reference viewed: 7 (4 ULg) Factors controlling soil organic carbon persistence along an eroding hillslope on the loess beltWiaux, François; Cornelis, Jean-Thomas ; Vanclooster, Marnik et alin Soil Biology & Biochemistry (2014), 77Detailed reference viewed: 21 (5 ULg) The hillslope as elementary unit to access the soil C balance by studying the impact of soil erosion on organic carbon sequestration and soil respirationWiaux, François; Cornelis, Jean-Thomas ; Cao, Wei et alScientific conference (2013)Detailed reference viewed: 7 (1 ULg) The synergetic effect of moisture protection, substrate quality and biotic acclimation on soil organic carbon persistence along a cultivated loamy hillslopeWiaux, François; Vanclooster, Marnik; Cornelis, Jean-Thomas et alPoster (2013)Abstract : The combination of hydrologic, geomorphic and biogeochemical approaches is required to determine organic carbon (OC) persistence and dynamics within landscapes. Here, we used soil in-situ ... [more ▼]Abstract : The combination of hydrologic, geomorphic and biogeochemical approaches is required to determine organic carbon (OC) persistence and dynamics within landscapes. Here, we used soil in-situ surface heterotrophic respiration measurement as an indicator of OC persistence along a hillslope (crop field on the loess belt Under temperate climate), characterized by an important erosion-induced OC stock colluvium downslope. Along this topographical gradient, we quantified the space-time structure of soil water and temperature, and soil OC amount and quality (from a chemical point of view based on NaOCl oxidation) in relation to CO2 fluxes. We used a Generalized Least Square (GLS) regression model to identify the role of each abiotic factor as well as their interactions on observed soil respiration rates, and to calculate time-average values of these CO2 fluxes at each studied slope positions. [less ▲]Detailed reference viewed: 45 (1 ULg) Distribution, leaching and flux measurements of contaminants in the vadose zone of industrial contaminated sites: a reviewFernandez de Vera, Natalia ; Vanclooster, Marnik; Brouyère, Serge Report (2012)This document is a review of state of science regarding flux measurement technologies in the vadose zone. Initially, a description of distribution and leaching of inorganic contaminants in the vadose zone ... [more ▼]This document is a review of state of science regarding flux measurement technologies in the vadose zone. Initially, a description of distribution and leaching of inorganic contaminants in the vadose zone is provided. Such description is followed by a review of vadose zone techniques that are applied for measuring contaminant fluxes. At the end of the document the applicability of such techniques to industrial contaminated sites is discussed. [less ▲]Detailed reference viewed: 18 (5 ULg) Space-time dynamics of soil respiration link to the C pool distribution at the hillslope scaleWiaux, François; Cornelis, Jean-Thomas ; Van Oost, Kristof et alin Geophysical Research Abstracts (2012), 14(EGU2012), 7937Abstract : A crucial issue in soil C dynamics modelling is to develop models suitable for regional scale, but based on local and short-time scale observations. Recent research has illustrated the strong ... [more ▼]Abstract : A crucial issue in soil C dynamics modelling is to develop models suitable for regional scale, but based on local and short-time scale observations. Recent research has illustrated the strong linkage between SOC dynamics and landscape processes. There is increasing evidence that lateral fluxes of SOC, sediment and water will further enhance the variability of SOC dynamics, especially on agricultural land. Hence, in this study, we aim to improve our understanding of soil C dynamics by quantifying the soil respiration response of carbon pools at different positions along a slope catena, characterized by different soil moisture and temperature conditions and by different SOC stock and C pool distributions. The study was performed on a hillslope in the belgian loamy belt. Time series of soil moisture, temperature and surface CO2 fluxes were monitored on a regular basis (at least once a week, during spring and autumn 2011) along the hillsope, at the soil surface. At the same positions, soil cores (1 to 1.5 m depth) were collected and analyzed for SOC, C distribution (using a chemical fractionation), mineral oxides (oxalate extractions), pH, and texture. Our results show that substantial lateral transport of soil materials takes place along this hillslope, with a continuous burying of surface C and minerals at the bottom of the slope. This results in the development of a colluvial soil with an increasing SOC stock. This colluvial C stock mainly consists of labile C (66%), and this labile C stock in the colluvium is 3.5 higher than the labile C stock at the other slope positions. This stock is thus poorly stabilized and has a higher potential for mineralization. The other part of this C stock is stabilized by organo-mineral associations (19%) or is recalcitrant C (15%). Compared to the other slope positions, this colluvial stable C stock is significant, as it is 1.5 to 2 times higher. The spatial gradient of the measured soil respiration is consistent with the previous C pool distribution observations along the hillslope, since there is a significant higher respiration at the bottom of the slope (colluvial area) than at the other slope positions. The measured temporal dynamics of the soil respiration is explained by moisture and temperature variations. This measured space-time dynamics, completed with further additional field measurement campaigns, will be the basis for calibrating and validating hillslope scale soil C turn-over models. [less ▲]Detailed reference viewed: 24 (3 ULg) Valorisation de la Carte Numérique des Sols de Wallonie et d’une base de données disponible en analyse de sols, dans le cadre de l’évaluation du risque de pollution des eaux souterraines par les pesticidesBah, Boubacar Billo ; Vanclooster, Marnik; Oger, Robert et alin Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2011), 15(S2), 709-726This study shows how the Digital Soil Map of Wallonia and the associated soil database Aardewerk can be combined with the MetaPEARL model to assess the sensitivity of agricultural soils to pesticide ... [more ▼]This study shows how the Digital Soil Map of Wallonia and the associated soil database Aardewerk can be combined with the MetaPEARL model to assess the sensitivity of agricultural soils to pesticide transfer into underground water tables in Wallonia (Southern Belgium). MetaPEARL is based on an analytical expression which describes the concentration of leached pesticides at the soil profile bottom depending on available data on soil characteristics, climate and pesticide properties. The results show an important soil sensitivity to pesticide transfer with a coefficient of retention on organic matter (Kom) very weak (about 10 dm3.kg-1) or with a relatively high half-life time (DT50 about 60 days). In this case, the pesticide is weakly retained by soil organic matter or slowly degraded and then stays available in the soil and can be quickly leached during rainfalls. In other respects, the pesticide sensitivity to leaching is strongly correlated with soil texture and its organic matter content. It is also observed that the concentration of leached pesticide is strongly depending of the rainfall surplus (water flux into the soil or hydrous balance). A sensitivity analysis has shown that the model is very sensitive to soil thickness, to organic matter content, to the bulk density of the mineral fraction by textural classes and of the organic matter. Therefore, these pedological variables have to be assessed with the highest precision to avoid adding further uncertainty to the predictions obtained. On the basis of the most sensitive soil variables, the analysis of “spatial” uncertainty related to the results delivered by MetaPEARL, due to the consideration of an unique representative value by soil type and by region (deterministic approach), shows that this approach tends to under-estimate the concentration of pesticide leached in the soil. And that compared to the use of a stochastic simulation (probabilistic approach) which takes into account the soil characteristic variability within a given soil type. This stochastic approach allows also the calculation of a more relevant threshold of risk probability (percentile) which can be compared to an imposed standard in view to enhance a sustainable management of natural resources. [less ▲]Detailed reference viewed: 152 (17 ULg) PESTEAUX: Implementing MetaPEARL for the Walloon Region in BelgiumBah, Boubacar Billo ; Vanclooster, Marnik; Oger, Robert Scientific conference (2011, March 29)Detailed reference viewed: 15 (3 ULg) Valorisation de la Carte numérique des sols de Wallonie et des bases de données disponibles en analyse de sol, dans le cadre de l’évaluation du risque de pollution des eaux de surface et souterraines par les pesticidesBah, Boubacar Billo ; Oger, Robert ; Vanclooster, Marnik et alConference (2010, November 24)Detailed reference viewed: 35 (4 ULg) Evaluation de la sensibilité des sols au transfert de pesticides vers les eaux souterraines en Région wallonne (Belgique)Bah, Boubacar Billo ; Mattern, Samuel; Vanclooster, Marnik et alin Actes des 35èmes Journées du Groupe Francophone Humidimétrie et TraNsferts en milieux poreux (GFHN), Louvain-la-Neuve, Belgique, 23-25 novembre 2010 (2010, November)Cette étude présente l'utilisation du métamodèle MetaPEARL (Tiktak et al., 2006) pour évaluer la sensibilité des sols au transfert des pesticides vers les eaux souterraines en Wallonie. MetaPEARL prédit ... [more ▼]Cette étude présente l'utilisation du métamodèle MetaPEARL (Tiktak et al., 2006) pour évaluer la sensibilité des sols au transfert des pesticides vers les eaux souterraines en Wallonie. MetaPEARL prédit la concentration de pesticide lixivié au bas du profil pédologique en fonction de données facilement disponibles sur les sols, le climat, et les propriétés des pesticides. MetaPEARL a été appliqué pour quatre pesticides génériques A, B, C et D (FOCUS, 2000). Les résultats obtenus montrent une sensibilité plus importante des sols de Wallonie aux transferts des pesticides de type A et B, permettant ainsi de distinguer des régions relativement contrastées d’un point de vue de la sensibilité de leurs sols au transfert des pesticides vers les eaux souterraines. Ce contraste régional est corrélé d’une part à la variabilité régionale des teneurs en matière organique des sols, et d’autre part au gradient pluviométrique nord-sud observé en Wallonie. On constate également que la concentration en pesticide lixivié est plus importante en automne qu’au printemps. [less ▲]Detailed reference viewed: 50 (6 ULg) Évaluation de la sensibilité des sols au transfert des pesticides vers les eaux souterraines en Wallonie (Belgique) avec le métamodèle MetaPEARLBah, Boubacar Billo ; Mattern, Samuel; Vanclooster, Marnik et alin Milieux Poreux et Transferts Hydriques (2010), 56Cette étude présente l'utilisation du métamodèle MetaPEARL pour évaluer la sensibilité des sols au transfert des pesticides vers les eaux souterraines en Wallonie. MetaPEARL prédit la concentration de ... [more ▼]Cette étude présente l'utilisation du métamodèle MetaPEARL pour évaluer la sensibilité des sols au transfert des pesticides vers les eaux souterraines en Wallonie. MetaPEARL prédit la concentration de pesticide lixivié au bas du profil pédologique en fonction de données facilement disponibles sur les sols, le climat, et les propriétés des pesticides. MetaPEARL a été appliqué pour quatre pesticides génériques A, B, C et D (FOCUS, 2000). Les résultats obtenus montrent une sensibilité plus importante des sols de Wallonie aux transferts des pesticides de type A et B, permettant ainsi de distinguer des régions relativement contrastées d'un point de vue de la sensibilité de leurs sols au transfert des pesticides vers les eaux souterraines. Ce contraste régional est corrélé d'une part à la variabilité régionale des teneurs en matière organique des sols, et d'autre part au gradient pluviométrique nord-sud observé en Wallonie. On constate également que la concentration en pesticide lixivié est plus importante en automne qu'au printemps. [less ▲]Detailed reference viewed: 50 (5 ULg) Soil surface water content estimation by full-waveform GPR signal inversion in the presence of thin layersMinet, Julien ; Lambot, Sébastien; Slob, Evert C. et alin IEEE Transactions on Geoscience and Remote Sensing (2010), 48We analyzed the effect of shallow thin layers on the estimation of soil surface water content using full-waveform inversion of off-ground ground penetrating radar (GPR) data. Strong dielectric contrasts ... [more ▼]We analyzed the effect of shallow thin layers on the estimation of soil surface water content using full-waveform inversion of off-ground ground penetrating radar (GPR) data. Strong dielectric contrasts are expected to occur under fast wetting or drying weather conditions, thereby leading to constructive and destructive interferences with respect to the surface reflection. First, synthetic GPR data were generated and subsequently inverted considering different thin-layer model configurations. The resulting inversion errors when neglecting the thin layer were quantified, and then, the possibility to reconstruct these layers was investigated. Second, laboratory experiments reproducing some of the numerical experiments configurations were conducted to assess the stability of the inverse solution with respect to actual measurement and modeling errors. Results showed that neglecting shallow thin layers may lead to significant errors on the estimation of soil surface water content ($\Delta\theta$ > 0.03 $m^3/m^3$), depending on the contrast. Accounting for these layers in the inversion process strongly improved the results, although some optimization issues were encountered. In the laboratory, the proposed full-waveform method permitted to reconstruct thin layers with a high resolution up to 2 cm and to retrieve the soil surface water content with an rmse less than 0.02 $m^3/m^3$, owing to the full-waveform inverse modeling. These results suggest that the proposed GPR approach is promising for field-scale mapping of soil surface water content of nondispersive soils with low electrical conductivity and for instances when soil layering is encountered. [less ▲]Detailed reference viewed: 64 (0 ULg) A generalized frequency domain reflectometry forward and inverse modeling technique for soil electrical properties determinationMinet, Julien ; Lambot, Sébastien; Delaide, Géraldine et alin Vadose Zone Journal (2010), 9(4)We have developed a generalized frequency domain reflectometry (FDR) technique for soil characterization that is based on an electromagnetic model decoupling the cable and probe head from the ground using ... [more ▼]We have developed a generalized frequency domain reflectometry (FDR) technique for soil characterization that is based on an electromagnetic model decoupling the cable and probe head from the ground using frequency-dependent reflection and transmission transfer functions. The FDR model represents an exact solution of Maxwell’s equations for wave propagation in one-dimensional multilayered media. The benefit of the decoupling is that the FDR probe can be fully described by its characteristic transfer functions, which are determined using only a few measurements. The soil properties are retrieved after removing the probe effects from the raw FDR data by iteratively inverting a global reflection coefficient. The proposed method was validated under laboratory conditions for measurements in water with different salt concentrations and sand with different water contents. For the salt water, inversions of the data led to dielectric permittivity and electrical conductivity values very close to the expected theoretical or measured values. In the frequency range for which the probe is efficient, a good agreement was obtained between measured, inverted and theoretically predicted signals. For the sand, results were consistent with the different water contents and also in close agreement with traditional time domain reflectometry measurements. The proposed method offers great promise for accurate soil electrical characterization because it inherently permits maximization of the information that can be retrieved from the FDR data and shows a high practicability. [less ▲]Detailed reference viewed: 66 (3 ULg) Impact of short range variability of soil and substance properties on regional scale atrazine exposure to groundwaterVanclooster, Marnik; Bah, Boubacar Billo ; Oger, Robert et alPoster (2010)Detailed reference viewed: 15 (2 ULg) Development of a version of GeoPEARL for the Walloon region of BelgiumBah, Boubacar Billo ; Vanclooster, Marnik; Oger, Robert Scientific conference (2009, November)Detailed reference viewed: 28 (0 ULg) 1 2