Laboratoire d’Hydraulique Saint-Venant
Recherchez dans le site
Tutelle https://www.edf.fr/ Tutelle https://ecoledesponts.fr/ Tutelle https://ecoledesponts.fr/
Partager

Magali JODEAU

Magali JODEAU

Ingénieur Chercheur Expert EDF, Chercheur LHSV

à EDF depuis décembre 2007, rattachée au Laboratoire d'Hydraulique Saint-Venant depuis 2018

Formation

  • ENS-LYON Physique (2001-2004)
  • Master 2 HHGG UPMC (2003-2004)
  • Thèse 2007 : Morphodynamique d'un banc de galets en rivière aménagée lors de crue (Université Lyon 1) Directeurs de thèse : Michel Leclerc (INRS-ete, Canada) et André Paquier (Irstea Lyon)

Champs d'intérêt

  • Transport sédimentaire
  • Mesure des vitesses d'écoulement par LS-PIV
    Développement depuis 2009 du logiciel Fudaa-LSPIV avec Irstea et EDF DTG : téléchargement
  • Couplage Hydrodynamique - Biogéochimie
    Telemac3D-AED2

Enseignements

  • Master 2 HHGE (Hydrologie, Hydrogéologie, Géochimie environnementale) Sorbonne Université
  • Licence 3 Sciences de la Terre, Sorbonne Université
  • Formation continue ENPC Conduire un projet d'aménagements fluviaux
  • Formation itech EDF sédimentologie en milieu fluvial et en retenue
  • Journées Fudaa-LSPIV

Encadrements

Thèses en cours
  • Measurement and modelling of nutrient and contaminant flux dynamics at the water-sediment interface in aquatic environments - Thèse ENPC LEESU-LHSV, 2018- , Doctorant : Guilherme Calabró , Directeur de thèse : Régis Moilleron (LEESU), Co-Encadrants : Magali Jodeau (EDF - LHSV), Bruno Lemaire et Brigitte Vinçon-Leite (LEESU)
  • Dynamique des sédiments fins en rivière : suivi in situ des propriétés d’érosion/dépôt pour les modèles numériques - Thèse CIFRE EDF - IGE, Directeur de thèse : Cédric Legout (IGE), Co-Encadrants : Magali Jodeau, Germain Antoine(EDF - LHSV)
Thèses
  • 2016, Philippe Ung, Simulation numérique du transport sédimentaire - Aspects déterministes et stochastiques - Directeur de thèse : Stéphane Cordier (Université d'Orléans), Co-Encadrants : Emmanuel Audusse (ParisXIII), Sébastien Boyaval (ENPC LHSV), Nicole Goutal, Magali Jodeau (LHSV, EDF)
  • 2013, Germain Antoine, Dynamique des matériaux en suspension le long de rivières aménagées de montagne : exemple de l’Arc en Maurienne et l’Isère - Directeur de thèse : Michel Estèves (LTHE-IGE), Co-Encadrants : Benoit Camenen (Irstea), Magali Jodeau (EDF)

Publications

  • Subaquatic Relaxed Eddy Accumulation: A new technique to resolve benthic solute fluxes
    • Calabro Souza Guilherme
    • Dubois Philippe
    • Saad Mohamed
    • Lorke Andreas
    • Noss Christian
    • Boudahmane Lila
    • Lauret Olivier
    • Brigitte Vinçon-Leite
    • Jodeau Magali
    • Moilleron Régis
    • Lemaire Bruno J.
    , 2021 . The transport across the sediment-water interface of solutes, dissolved oxygen, nutrients and contaminants is of major importance for biogeochemical cycles and water quality in aquatic ecosystems. This exchange depends not only on biogeochemical processes and on temperature, but also strongly on near-bed currents. Eddy covariance measurements in a lake showed that oxygen benthic fluxes can vary over minutes to hours. However, the corresponding dynamics of nutrient and contaminant fluxes is still not fully understood. Common techniques fail to capture the turbulence-driven fluxes of interfacial transport for most chemical species, particularly in situ and at high temporal resolution. At the land-atmosphere interface, this issue is addressed with the relaxed eddy accumulation (REA), a conditional sampling technique. Samples are accumulated at constant flow rate in separated containers depending on the direction of the vertical flow. The vertical flux is finally assumed to be proportional to the concentration difference of sample pairs, which might be analysed in situ or at lab. The adaptation of the technique for measuring fluxes through the sediment-water interface is presented here. A portable prototype was developed, embedding both relaxed eddy accumulation and eddy covariance as a reference technique for validation. Vertical Dissolved oxygen fluxes were measured during ca. 10 min accumulation periods, at ca. 15 cm above the sediment, in spring and summer and at different sites: a laboratory flume with an artificial oxygen flux, a river branch, a creek, a shallow lake and an experimental lake. Oxygen fluxes measured with both techniques showed a good agreement, which validates both the technique and the prototype. The new device proves to be a promising tool to access benthic fluxes at high frequency over a flat sediment-water interface. First time series of nutrient fluxes will be presented.
  • Downstream erosion and deposition dynamics of fine suspended sediments due to dam flushing
    • Antoine G.
    • Camenen B.
    • Jodeau M.
    • Némery J.
    • Esteves M.
    Journal of Hydrology, Elsevier , 2020, 585 (5), pp.124763 . Fine sediment dynamics downstream dams is a key issue when dealing with environmental impact of hydraulic flushing. This paper presents an analysis of six field campaigns carried out during dam flushing events (in June 2006, 2007, 2009, 2010, 2011, and 2012) in the Arc- Isere river system in the Northern French Alps. Suspended sediment concentrations (SSC) and discharges were evaluated using direct measurements or/and 1D hydraulic modelling at up to 14 locations along the 120 kilometres-long river channel. The total suspended sediment flux (SSF) is analysed along the Arc and Isere rivers for each Arc dam flushing event. Uncertainties were quantified based on a propagation method of both measurement and modelling errors. The resulting confidence interval provides elements of discussion on the significance of the sediment mass balance between two consecutive measurement sites. Whereas the discharge time-series of each flushing event is roughly the same, the quantity of fine sediments removed from the reservoirs varied from 10,000 tons in 2007 to 40,000 tons in 2006. Also, a significant erosion is observed in the river system for some events (20,000 tons in 2007) while the SSF barely varied for other events (in 2009 and 2011). This detailed data set allows to identify specific locations in the river network where deposition or erosion occurred. This dynamics is closely related to both the hydrology in the upper Isere River and the morphology of the Arc and Isere rivers, which have been affected by the 2008 and 2010 floods. (10.1016/j.jhydrol.2020.124763)
    DOI : 10.1016/j.jhydrol.2020.124763
  • Telemac3D for aquatic ecological modelling: calibration of the coupled ecological library AED2
    • Piccioni Francesco
    • Vinçon-Leite Brigitte
    • Le Minh-Hoang
    • Lemaire Bruno J.
    • Casenave Céline
    • Hong Yi
    • Jodeau Magali
    • Pham Chi-Tuan ;
    • Vidal Javier
    • Goutal Nicole
    , 2019 . The monitoring and preservation of water quality is one of the main challenges in modern society. Anthropogenic stressors originated from urbanization and industrialization can have a strong impact on water resources in terms of pollutant release and nutrient enrichment. Together with the ongoing climate change, they can lead to the proliferation of primary producers and the eutrophication of the water bodies. Harmful algal blooms, and in particular cyanobacteria blooms, are an ever increasing concern worldwide as their occurrence strongly increases, expanding to higher latitudes due to warmer water temperature. Cyanobacteria are able to produce toxins that are dangerous to human health and represent a serious threat not only for the balances of an ecosystem but to human society as well. Aquatic ecological models are useful tools that can be used to simulate the biogeochemical cycle in a water body identifying the factors triggering events such as harmful algal blooms, in order to provide stakeholders with reliable projections for decision making. However, their calibration and validation often remains a challenging task: biological and chemical data deriving from field surveys are often sparse in space and time and, due to the complexity of the biogeochemical cycle, these models generally involve a high number of parameters to adjust. Aquatic ecological models need to rely on a robust hydrodynamic simulator, upon which the biogeochemical cycle is simulated. Telemac3D has recently been coupled by EDF R&D with the well-known ecological library Aquatic EcoDynamics (AED2). In this context, we aim to test the performance of Telemac3D coupled with AED2 on a full scale experimental site by comparison with high-frequency in situ data. The study site is a small and shallow urban lake located in the east of Great Paris metropolitan area. The lake suffers from repeated and severe harmful algal blooms in summer and autumn. Aside from the traditional monitoring via field campaigns and water sampling, the study site is equipped with specific sensors recording data at high-frequency (every 10 minutes) for water temperature, pH, dissolved oxygen and for the concentration of specific pigments to monitor phytoplankton growth (chlorophyll-a and phycocyanin, considered as proxies for total biomass and cyanobacteria biomass, respectively). The use of high-frequency data allows on the first hand to test the capability of the model to reproduce daily cycles and rapid blooms events spanning only a few days, and on the other hand to gain in computational time while calibrating the model on a short time periods of two to three weeks. Model results are compared with water temperature data at different depths to test the ability of the coupled hydrodynamic model to reproduce thermal stratification in the water column. The ecological module AED2 is set up to simulate two main algal groups present in the study site, green algae and cyanobacteria. High-frequency observations of chlorophyll-a and phycocyanin are used to calibrate the ecological model AED2 and to test its outcomes. Model results show that Telemac3D coupled with AED2 is able to correctly reproduce biomass growth in a water body over short bloom events spanning roughly three weeks. Even though a feedback originated from strong biomass growth can be detected in water temperature results, the model is also able to correctly reproduce thermal water column stratification. These possible feedbacks need to be taken into account when calibrating the heat-exchange budget at the water-air interface.
  • High frequency monitoring of biogeochemical processes in a small and shallow lake
    • Calabro Souza Guilherme
    • Piccioni Francesco
    • Hong Yi
    • Dubois Philippe
    • Saad Mohamed
    • Casenave Céline
    • Jodeau Magali
    • Moilleron Régis
    • Lemaire Bruno J.
    • Brigitte Vinçon-Leite
    , 2019 . Small and shallow inland water bodies are important providers of ecosystem services, e.g. in metropolitan areas. Their presence is massive in most landscapes, and they contribute substantially to global biogeochemical cycles. The dynamics of their ecological functioning is fast (e.g., algal blooms can appear and recede within a few days) and its spatial variability can be high. Understanding these processes requires high-frequency measurements. Within the ANR ANSWER and the AquaREA project, biogeochemical processes are monitored and modelled in a small and shallow lake, both in the water column and at the sediment-water interface. The study site is a 0.12 km2 and 2.3 m deep lake in the Greater Paris. Physical-chemical variables (water temperature, conductivity, pH, dissolved oxygen), chlorophyll-a fluorescence, a proxy of total phytoplankton biomass, and phycocyanin fluorescence, a proxy of cyanobacteria biomass, have been monitored since 2015 at high frequency (every 10 min) at three different points and two depths. Nitrate concentration is also continuously monitored by UV and visible light spectroscopy. An innovative system, based on the atmospheric technique Relaxed Eddy Accumulation, is under development and will enable to quantify the fluxes of nutrients and greenhouse gases at the water-sediment interface. This continuous monitoring dataset is used for phytoplankton modelling and bloom forecast.
  • Numerical Simulation of the Dynamics of Sedimentary River Beds with a Stochastic Exner Equation
    • Audusse Emmanuel
    • Boyaval Sébastien
    • Goutal Nicole
    • Jodeau Magali
    • Ung Philippe
    ESAIM: Proceedings and Surveys, EDP Sciences , 2015, 48, pp.321 - 340 . At the scale of a river reach, the dynamics of the river bed is typically modelled by Exner equation (conservation of the solid mass) with an empirical solid flux of transported sediments, which is a simple deterministic algebraic formula function of i) the sediment physical characteristics (size and mass) and of ii) the averaged hydrodynamical description of the ambient water flow. This model has proved useful, in particular through numerical simulations, for hydraulic engineering purposes (like estimating the mass of sediments that is drained through an open dam). Though, the model is also coarse. And its applicability at various space and time scales remains a question of considerable interest for sedimentologists. In particular, physical experiments from the grain scale to the laboratory scale reveal important fluctuations of the solid flux in given hydrodynamical conditions. This work is a preliminary study of the coupling of a stochastic Exner equation with a hydrody-namical model for large scales. (Stochastic models with a probabilistic solid flux are currently being investigated, but most often only from the viewpoint of theoretical physics at the grain scale.) We introduce a new stochastic Exner model and discuss it using numerical simulations in an appropriate test case. (10.1051/proc/201448015)
    DOI : 10.1051/proc/201448015
  • Application de la méthode LSPIV pour la mesure de champs de vitesse et de débits de crue sur modèle réduit et en rivière
    • Hauet A.
    • Jodeau M.
    • Le Coz J.
    • Marchand B.
    • Die Moran A.
    • Le Boursicaud R.
    • Dramais Guillaume
    La Houille Blanche - Revue internationale de l'eau, EDP Sciences , 2014, 3, pp.16-22 . La technique LSPIV (Large Scale Particle Image Velocimetry) permet de mesurer les vitesses de surface d'un écoulement par analyse de séquence d'images. Pour faciliter l'application opérationnelle de la méthode, un logiciel, Fudaa-LSPIV, a été développé par la société DeltaCAD dans le cadre d'une collaboration entre EDF et Irstea. Deux applications en laboratoire et en rivière sont présentées : (i) couplée avec des mesures de hauteur d'eau et de bathymétries, la LSPIV a permis d'estimer des paramètres de Shields sur le modèle physique à fond mobile du Vieux-Rhin ; (ii) le logiciel a été utilisé pour procéder à des analyses de sensibilité pour paramétrer ainsi au mieux les stations LSPIV de mesure de débit en crue de rivières cévenoles. (10.1051/lhb/2014024)
    DOI : 10.1051/lhb/2014024
  • Sediment transport modelling : Relaxation schemes for Saint-Venant -- Exner and three layer models
    • Audusse Emmanuel
    • Chalons Christophe
    • Delestre Olivier
    • Goutal Nicole
    • Jodeau Magali
    • Sainte-Marie Jacques
    • Giesselmann Jan
    • Sadaka Georges
    , 2012 . In this note we are interested in the modelling of sediment transport phenomena. We mostly focus on bedload transport and we do not consider suspension sediment processes. We first propose a coupled numerical scheme for the classical Saint-Venant -- Exner model. It is based on a relaxation approach and it works with all sediment flux function. We exhibit that this coupled approach is more stable than the splitting approach that is mostly used in industrial softwares. Then we derive an original three layers model in order to overcome the difficulties that are encountered when using the classical Exner approach and we write a related relaxation model.
  • Sediment transport modelling : relaxation schemes for Saint-Venant - Exner and three layer models
    • Audusse Emmanuel
    • Chalons Christophe
    • Delestre Olivier
    • Goutal Nicole
    • Jodeau Magali
    • Sainte-Marie Jacques
    • Giesselmann Jan
    • Sadaka Georges
    ESAIM: Proceedings, EDP Sciences , 2012, 38, pp.78-98 . In this note we are interested in the modelling of sediment transport phenomena. We mostly focus on bedload transport and we do not consider suspension sediment processes. We first propose a numerical scheme for the classical Saint-Venant - Exner model. It is based on a relaxation approach for the whole system and it works with all sediment flux function. The stability of the scheme is investigated and some numerical tests are proposed. We exhibit that this coupled approach is more stable than the splitting approach that is mostly used in industrial softwares. Then we derive an original three layers model in order to overcome the difficulties that are encountered when using the classical Exner approach and we present a related relaxation model. (10.1051/proc/201238005)
    DOI : 10.1051/proc/201238005