Pegase modelling studies applied to micropollutants: use cases

For the last years, PEGASE model has been used in two studies aiming at better assessment of the source and behaviour of micropollutants in the rivers network. In the first study, with financial support from INERIS1, the PEGASE model has been used to simulate the fate of micropollutants (Cd, Zn & Cu) within the basins of the Meuse and the Adour. The choice of the modelled micropollutants and sub-basins has been performed in agreement with INERIS, the involved Water Agencies and the Aquapole. A major selection criterion was the availability of data (discharges and in-situ measurements). For the second study, the PEGASE model has been adapted to describe the cocaine fate (or rather one of its stable metabolite: benzoylecgonine–BZE) in surface water. The BZE has been added to the model as an additional micropollutant, thanks to the implementation of a new state variable. Simulations of BZE have been done in Belgium, where many measurements from the COWAT project [3] were available. The first results show a good matching between calculated and measured values. The ability of the model to simulate the fate of micropollutants (including emerging substances) within surface water has been demonstrated, but still requires enhancements and extension to other substances and sub-basins. In addition, these studies have shown the huge work remaining in discharge inventories

TRANSNATIONAL MODELING OF THE SURFACE WATER QUALITY OF THE INTERNATIONAL RIVER BASIN DISTRICT MEUSE WITH PEGASE

The PEGASE Model has been applied at the entire International River Basin District of the Meuse. The poster presents different sub-basin applications on (i) the Chiers (Luxembourg + Belgium Walloon Region and French Rhin-Meuse Basin, 2000-2006) for the reference years 2000 and 2002 and prospective scenario 2015, (ii) International simulation performed (during 2005-2006) upstream (up to the Belgian border) for the reference year 2002, (iii) Current coordination between BE-Flemish Region and NL for downstream simulations of historical situation and (iv) prospective scenarios : International databases for a single reference year on the whole Meuse Distric

Le logiciel PegOpera : un outil pour la gestion intégrée des eaux de surface

Le logiciel PegOpera inclut la version 5 du modèle Pegase (Planification Et Gestion de l’ASsainissement des Eaux) et une nouvelle interface graphique. PegOpera est un outil personnalisé utilisé par les gestionnaires de l’eau et opérationnel dans les champs d’applications de la Gestion Intégrée des Ressources en Eau (assainissement, DCE, NQE, …)

Solar wind control of auroral substorm onset locations observed with the IMAGE-FUV imagers

peer reviewedThe FUV imagers on board the IMAGE satellite provide multispectral snapshots of the polar region every 2 min. The combination of the Wide-Angle Imaging Camera (WIC) with SI12 (Doppler shifted Lyman-alpha) and SI13 (135.6 nm) spectral imagers is used to discriminate between the electron and the proton aurora. We describe a statistical study of the location of 78 substorms observed close to the 2000-2001 winter solstice. The latitudinal distribution of the onsets observed with WIC is asymmetric with a median at 65.6° MLAT and a full width at half maximum (FWHM) of 3.5°. Their local time distribution is concentrated between 2000 and 0200 MLT with a median at 23.4 +/- 0.3 hours MLT and a FWHM of 1.8 hours. No statistically significant difference is found in the spatial distribution of the proton and electron onsets. All onsets take place within a region of preexisting proton precipitation, indicating that substorm initiation occurs in regions of stretched but dipole-like field lines that cross the equatorial plane close to the Earth. Latitudes of substorm onsets are located at a variable distance from the poleward FUV auroral boundary but remain at a nearly constant distance from the equatorward limit of both proton and electron auroral ovals. The magnetic latitudes of the onsets are correlated with some of the solar wind plasma properties measured by the ACE satellite prior to the substorm breakup. In particular, a clear anticorrelation is found between the onset MLAT and the 1-hour averaged solar wind dynamic pressure. A decrease of the onset latitude is also observed for larger B intensity values. No dependence of the onset MLT on the solar wind speed is observed, in contrast to the relationship expected from the thermal catastrophe model for substorm initiation. Our results are in agreement with models locating the initial instability in the near magnetosphere such as the near-Earth current disruption models

Pegase, a model dedicated to Surface WAter Quality Assessment that helps stakeholders implementing the WFD

Pegase, a model dedicated to surface water quality assessment that helps stakeholders implementing the WFD. That presentation showed 2 different applications directly made by the stakeholders in charge of the water management at the basin scale. The end-users analysed results of the Pegase model in the scope of implementation of the WFD. Differents scenarios were build in order to simulate the way to reach the good status for water bodies. Associated costs were estimated and relevant decisions were oriented using the results of the numerical Pegase tool

Water Framework Directive and Modelling Using PEGOPERA Simulation Software

peer reviewedaudience: researcher, professional, studentThe Water Framework Directive 2000/60/EC (WFD) established a framework for community action in the field of water policy. To implement the WFD, the competent authorities for watershed management should use modelling techniques to establish, for example, the pressure/impacts relationship. The PEGOPERA modelling tool (composed of the water quality model PEGASE and a friendly Graphical User Interface), has been developed in order to be compliant with the requirements of the WFD. PEGASE is a physicochemical model describing the behaviour of whole river systems, at various scales, from tens to tens of thousands km². The specificity of the model is its ability to work at a high spatial resolution not only for small river basins (water body level), but also for large drainage networks. Already used by several basin management competent authorities, the PEGOPERA modelling tool proved to be an efficient tool for helping in surface water management from local up to the international district level and is therefore an operational numerical tool for WFD implementatio

PEGASE: UN MODÈLE INTÉGRÉ BASSIN HYDROGRAPHIQUE/ RIVIÈRES: PREMIÈRE APPLICATION TEST À LA COCAÏNE.

Le modèle PEGASE (Planification Et Gestion de l’ASsainissement des Eaux), développé à l’Aquapôle de l’Université de Liège a été utilisé pour réaliser une première simulation test de la cocaïne dans le réseau hydrographique belge. La principale conclusion de cette simulation test est qu’il est possible de simuler le devenir des dérivés de la cocaïne dans les eaux de surface ; cela démontre également la cohérence des mesures réalisées dans le cadre de l’étude COWAT. Des améliorations mineures au modèle PEGASE et aux données d’entrée seraient cependant souhaitables pour améliorer cette modélisation (possibilité de faire varier l’équivalent-habitant par zones).PEGASE: UN MODÈLE INTÉGRÉ BASSIN HYDROGRAPHIQUE / RIVIÈRES: PREMIÈRE APPLICATION TEST À LA COCAÏNE

Energy-flux relationship in the FUV Jovian aurora deduced from HST-STIS spectral observations

[1] Far ultraviolet spectral observations of the Jovian aurora have been made since 1997 with the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope at low spectral resolution. The combination of the spectral resolution with the intensity variation along the STIS slit provides information on the latitudinal variation of the precipitating auroral electron energy flux and the mean electron energy, from which the electron current density at the top of the atmosphere can also be deduced. It is found that the mean electron energies associated with the main oval lie in the range 30 - 200 keV and show a tendency to increase with the precipitating energy flux. The current densities lie in the range similar to 0.04 - 0.4 muA m(-2), consistent with previous estimates, and are also positively correlated with the energy flux. The observed relationship between the auroral time-integrated energy fluxes and the electron energies in the main oval is compatible with that expected from Knight's theory of field-aligned currents. The best agreement between the observed data and the Knight curves is obtained for an electron temperature of T-e = 2.5 keV and a source density N = 0.003 cm(-3), that is within the range of values observed in the equatorial plane during the Voyager flybys. No systematic dependence of the electron energy with magnetic local time is found, but the morning sector around 0800 MLT shows greater variability than other regions of the oval. Analysis of time-tagged data shows that the main oval energy flux usually varies steadily over the several minute intervals of observation and that the mean electron energy usually undergoes correlated variations such that the current density remains relatively constant. It is shown that these overall properties are also consistent with Knight's theory of auroral electron acceleration associated with field-aligned current flow, from which it is inferred that the temporal variations observed are often due to slow changes in the magnetospheric "source'' electron parameters in the presence of near-steady magnetosphere-ionosphere coupling currents. By contrast, time-integrated emissions in the polar region are found to be associated with similar mean electron energies to the main oval but with typically smaller energy fluxes and current densities. Pressure balance arguments are advanced, which indicate that the brighter of these emissions must be associated with an auroral acceleration mechanism perhaps similar to that operative in the main oval, while it remains possible that the weaker emissions could result from precipitation from a quasi-isotropic hot magnetospheric electron source

Lessons learned from a partnership between the University of Liège and Water Agencies for the management of surface water quality

peer reviewedAn innovative partnership has been established between a university research team (R&D unit of the Aquapôle, University of Liège) and public authorities responsible for the protection of water resources and aquatic environments [French Water Agencies, Walloon and Flemish Administrations (Belgium)]. The main objective of this partnership is the water resources management by Agencies and Administrations by providing them with an innovative and operational decision-making tool enabling them to fulfill their regional (intervention programs, SDAGE …), national and international missions (WFD, European reporting ...). In order to achieve this goal, the partnership is based on the development of a software suite that meets the expectations of operators (the PEGOPERA software). This development strategy, based on the partners’ needs, provides a direct benefit to the quality improvement of aquatic environment