68 research outputs found
Veiligheid en gezondheid in noodsituaties : een doorlichting van de welzijnsreglementering voor wat betreft brandweer, politie, civiele bescherming en defensie ingezet tijdens noodsituaties in België
No full textDe Europese Kaderrichtlijn 89/391/EEG van 12 juni 1989 diende als basis voor de Belgische welzijnsreglementering. Zowel de EU als België maakt gewag van de specificiteit van brandweer, politie, civiele bescherming en defensie. Deze bijdrage geeft de resultaten weer van een doorlichting van de omzetting van de EU-regelgeving naar Belgisch recht gezien vanuit het standpunt van deze vier werkgevers. Er wordt aangetoond dat de Belgische wetgeving ruimer en strenger is dan wat Europa eist. Dit zorgt voor praktische problemen in noodsituaties, bijvoorbeeld op het vlak van de systematische risicobeheersing. Er wordt ook vastgesteld dat de vakliteratuur die het doen en laten in de interventiezone beschrijft op haar beurt, wanneer het over aan veiligheid en gezondheid van de werknemers gerelateerde onderwerpen gaat, niet refereert aan de welzijnsreglementering. Ten slotte wordt aangetoond dat sommige EU-lidstaten voor een minder strenge omzetting van de Kaderrichtlijn hebben gekozen en hierbij meer begrip tonen voor de specificiteit van de zogenaamde “interveniërende disciplines”. Op het einde van deze bijdrage volgt een reeks aanbevelingen
Closed loop GPR data inversion for soil hydraulic and electric property determination
No full textWe propose an integrated electromagnetic-hydrodynamic inverse modeling approach for identifying field-scale unsaturated soil hydraulic properties and electric profiles from off-ground time-lapse ground-penetrating radar data. Hydrodynamic modeling based on the one-dimensional Richards' equation with homogeneous soil hydraulic parameters is used to physically constrain the full-wave radar electromagnetic inverse problem in a closed loop. Significant effects can be observed of water dynamics on the time-lapse radar data and numerical studies demonstrate the uniqueness of the inverse solution. The results suggest that the method is promising for non-invasive characterization of the shallow subsurface and monitoring of its dynamics.GeotechnologyCivil Engineering and Geoscience
Quality assessment of environmental simulation scenarios scientific, expertise, interpretive and participatory methods based on mathematical, epistemological and socio-anthropological approaches
No full textSimulation scenarios, defined as parameters with a physical meaning used with scientific models, are often used to supplement the limits and avoid the costs of experimental approaches, and to forecast the environmental consequences of regulatory decisions. Their quality assessment is important to support decisions in the public domain and avoid choiceswith unwanted effects. Building onmathematical, socio-anthropological, philosophical, and scientific developments, this study defines a generic framework for scenarios quality assessment, develops specific methods and adequacy criteria for regulatory scenarios and tests their applicability, limits and interest.
Quality is defined as the adequacy for a given use. Representativeness, theoretical consistency, logical consistency, juridical conformity and political criteria are defined. Two routes for quality assessment are defined: an expertise route making interpretation choices transparent, and a participatory route opening interpretation choices to citizens. Those routes are tested, respectively, with case studies of diffuse pollution simulation scenarios for groundwater and bees exposure to pesticides. The framework allows to assessmultiple quality components, taking into account the links between them(including the juridical, scientific and political components) while preserving their specificity. It highlights the limits of the scientific knowledge in a regulatory context, makes transparent the choices and uncertainties, and allows to assess the social acceptability of such uncertainties and of the use of the scenarios. Due to the lack of a binding political mandate in our case studies, the possibility of the incorporation of the framework in formal democratic processes is still to be demonstrated.(AGRO 3) -- UCL, 201
Non-occlusive mesenteric ischemia: two case reports and a short review of the literature
No full textCaractérisation de la pollution par les nitrates dans la masse d'eau souterraine des sables du Bruxellien/Yprésien en Région de Bruxelles-Capitale
No full textDans cette étude, nous évaluons la vulnérabilité à la pollution nitrique de la masse d'eau des Sables du Bruxellien/Yprésien en Région de Bruxelles Capitale à l'aide de modèles statistiques et conceptuels
Cartographie de la pollution des masses d'eau souterraine des sables bruxelliens par le nitrate
No full textIntroducing time variability and sampling rate in the mapping of groundwater contamination by means of the Bayesian Maximum Entropy (BME) method
No full textMapping and source identification of groundwater pollution by nitrate : theory and application to the Brusselian sand groundwater body
No full textThis thesis aimed to improve our understanding of groundwater pollution by nitrate at the regional scale of the Brusselian sand groundwater body (Belgium). Despite all the nitrate reduction actions that were undertaken to meet European directives, this study area still presents one of the highest groundwater nitrate concentrations of the Walloon Region. Further assessing the pollution levels of groundwater and identifying the contamination sources are therefore needed for designing sustainable water management strategies.
Our first main objective was to assess groundwater contamination at the regional scale by mapping the nitrate concentrations. The locations where groundwater quality properties were measured are scarce and sparsely distributed over space. We therefore used a data fusion method in order to improve the mapping quality of groundwater nitrate concentrations in areas located far away from monitoring stations.
The transfer time of nitrate to the aquifer is one of the reasons that could explain the lack of improvement in water quality. We estimated the travel time of percolating water through the vadose zone.
Our second main objective was to identify sources of groundwater nitrate pollution in the study area. Two statistical methods were used to link the measured nitrate concentrations with land and land use attributes. The isotopic signature of groundwater nitrate allowed to identify the source of pollution observed in some monitoring stations, and gave insight about processes affecting the contamination.(AGRO 3) -- UCL, 200
Yearly cropland mapping over large areas with high resolution satellite image time series
No full textWith human population growth, shifts in diets, biofuel development and climate change, the food supply system is subject to increasing pressures. In this context, timely and dependable information on crop production becomes crucial for market stability and food security. In spite of advances in satellite systems and data processing, there is a disconnect between operational cropland mapping and the state-of-the-art. This thesis seeks to bridge this gap by capitalizing on available land cover maps and by optimizing the satellite inputs. First, priority areas are identified for all countries to strategically allocate future mapping efforts. Second, methods are proposed to enable regular cropland mapping over large areas in the absence of in situ calibration data. The combination of calibration data carefully selected from available land cover maps and spectral-temporal features derived from the satellite image time series yields spatially consistent results with an accuracy that varies depending on the landscape being mapped. The features are stable over space and time and reduce the intra-class variability which in turn improves generalization. Finally, the spatial resolution requirements of the imagery can be anticipated by quantifying the fragmentation of the agricultural landscapes. This relationship allows optimizing the resolution to reduce the data volume and selecting the appropriate imagery to achieve reliable area estimation. These developments are essential building blocks towards an operational cropland mapping system and an improved global agriculture monitoring.(AGRO - Sciences agronomiques et ingénierie biologique) -- UCL, 201
Quantifying the local-scale uncertainty of estimated actual evapotranspiration
No full textIn this study, we quantified the local-scale uncertainty of the actual evapotranspiration estimated from a water balance approach combining two soil-water-content measurement techniques (time-domain reflectometry and neutron probe sounding). The local-scale uncertainty was quantified for 28 sampling points located within a small maize cropped field. This was done by determining progressively the expected value and uncertainty on soil-water content, soil-water storage, soil-water storage variation and on bottom flux. This latter term was quantified using two different hydraulic conductivity curves (HCC), derived from a pedotransfer function (PTF) and from field measurements. Results show that uncertainty on a soil water storage estimate for the considered experimental measurements in terms of standard deviation range between 9.72 and 10.37 mm. This uncertainty is related mainly to the calibration of the soil-water content measurement instruments. For a soil-water storage variation estimate, the uncertainty is smaller, with values ranging between 3.48 and 5.42 mm. In this case, the main component of the total variance is the instrumental variance and the variance resulting from the technique used to integrate soil-water-content measurements. The expected values and uncertainties for the bottom fluxes were significantly different for the two different HCC characterization techniques in some places in the field. For estimated ET fluxes with in situ estimated HCC results show that the uncertainty ranges in terms of standard deviation between 3.82 and 5.97 mm. It should be stressed that these values can be considered as very low and that a better precision is probably very difficult to obtain as all sensitive factors contributing to the ET variance have been determined in a consistent and optimal way. Finally, it is shown that the uncertainties in estimated HCC with PTFs may result in large uncertainties in estimated ET, questioning thereby the use of PTFs in characterizing the field water balance. Copyright (C) 2004 John Wiley Sons, Ltd
- …
