Seminars & media

* For the online seminars, contact us to receive a link.

  • 12 May 2023, 15 h (room Galilée, Antony & online) : Seminar by Andrea Ficchi (Politecnico di Milano), Projets PRINTFLOODS (Prediction Intelligence for Floods) et CLINT (Climate Intelligence). Machine-learning enhanced forecast of tropical cyclone rainfall for anticipatory humanitarian action
  • 28 March 2023, 11 h (room Galilée, Antony & online):
    • Alice Cameijo, intern at CEA, presents her work on « AI methods and example of application to geophysics: estimation of the number of sources detected on an infrasound sensor antenna »
    • Pierre Audraud, PhD Candidate at CEA, presents his work on « Rapid estimation of tsunami currents and inondation using deep learning algorithms »
  • 14 March 2023, 11 h (room Galilée, Antony & online): Fabien Pasquet (DREAL Centre – Val-de-Loire), presents about the work and tasks in flood forecasting and hydrometry.
  • 9 March 2023, 11 h (room Galilée, Antony & online): Fernando Neves Lima, professor at the Federal University of Itajubá (Brazil), presents his work on the variability of precipitation during floods through a study on an urban watershed.
  • 16 January 2023, 14 h (room Galilée, Antony & online): Seminar of Julien Lerat, researcher at CSIRO (Canberra, Australia), on the works carried out in collaboration with the Bureau of Meteorology and the University of New South Wales, « From hydro-climate model to services: case study of the AWRA modelling system » (more: here and
  • 9 January 2023, 14 h (room Galilée, Antony & online): Seminar of Laure Baratgin, PhD candidate at LMD (Laboratoire de Météorologie Dynamique, Paris/Palaiseau), on the topic « Hydropower modelling in ORCHIDEE ».
  • 13 Decembre 2022, 11 h (room Galilée, Antony & online): Seminar by Chloé Maffré, engineer at « Direction Antilles – Guyane de Météo-France, on the topic « Guyanese climate ».
  • 8 Decembre 2022, 14 h (Campus Jussieu, Paris & online): PhD defence of Paul Astagneau [in French], « Pistes d’amélioration de la généralité et de l’efficacité d’un modèle opérationnel de prévision des crues » (room TEB, T 46/56 N2). Abstract
  • 7 October 2022 (Montpellier opera) : Guillaume Thirel participated to the round table entitled « L’eau, l’Homme, la vie », organised par the Le Point journal during the Futurapolis Santé 2022 event. Video.
  • 16 September 2022, 14 h (room Galilée, Antony & online): researchers from Canada are visiting the HYDRO Team in Antony (see here for more info):
  • 7 July 2022, 14 h (room Monod & online): Anthony Lemoine, former PhD candidate and currently doing his post-doctoral research at IGE Grenoble & INRAE Lyon, presents his current work on « Nivo-glaciological changes in Alpine catchments: impacts on hydrological regimes and aquatic ecosystems ».
  • 15 March 2022: Pierre Brigode (visiting scientist at the HYDRO team) and Vazken Andréassian contributed to answer the question « How do small springs become great rivers? » [in French], published at « The Conversation Junior » (here)
  • 26 February – 6 March 2022: The HYDRO team participates in the « Salon international de l’Agriculture » (Agricultural Show) in Paris, Porte de Versailles, sharing their research and expertise on water and water-related risks: interview with Vazken Andréassian on Saturday 26 February, and interview with Léonard Santos on Saturday 5 March. More here.
  • 22  February 2022, 14 h (online): Seminar by Alberto Assis dos Reis (UFMG/Cemig, Belo Horizonte, Brazil). Developing a seamless medium- to long-range flow forecast to improve the prediction of hydropower generation in Brazil. Abstract.
  • 10 February, 9h: Vazken Andréassian participated in the Public hearing on « Scientific and technological aspects of quantitative water management », at the National Assembly and the Senate, organized by OPECST (Office parlementaire d’évaluation des choix scientifiques et technologiques/ Parliamentary office for the evaluation of scientific and technological choices). The presentation was titled « What impact of climate change on water resources » (in French). See the program here and the recording here. 
  • 10  December 2021, 13 h (online): PhD defence of Alberto Assis dos Reis, Universidade Federal de Minas Gerais, supervised by Wilson S. Fernandes (UFMG, Belo Horizonte, Brazil), co-supervised by M.H Ramos (HYDRO Team INRAE, Antony). Developing a seamless medium- to long-range flow forecast to improve the prediction of hydropower generation in Brazil.
  • 30 November 2021, 14 h (online): Seminar by Emixi Sthefany Valdez Medina, PhD candidate at Université Laval, Québec, under the supervision of François Anctil, co-supervised by M.H Ramos of the HYDRO Team. Title: Choosing between post-processing precipitation forecasts or chaining several uncertainty quantification tools in hydrological forecasting systems.
  • 8 November 2021, 14 h (Sorbonne Université/Campus Jussieu & online): PhD defence of Antoine Pelletier (INRAE Antony): « Aquifers and rivers: can groundwater level data improve modelling of river low flows? » [in French] Abstract [read more= »Read more » less= »Read less »] River discharge results from numerous hydrological processes, which control the movement of water until it reaches the catchment outlet. Among these processes, those implying aquifers play a specific role because of the capacity to store water on various time scales, including the inter-annual scale. Indeed, the evolution of groundwater level is ruled by dynamics which can spread on several years, in their response to climatic variations. This phenomenon is known as aquifer memory: several successive dry years are likely to cause a more intense hydrogeological drought than a single dry year suffering from a rainfall deficit. This memory phenomenon is also observed for streamflow: it is then known as catchment memory. Accurately reproducing this memory in the dynamics of droughts is one of the pitfalls encountered by hydrological models when they simulate or forecast low flows. Reliable low-flow forecasting tools are essential to adapt to droughts that become more and more frequent, long and intense because of climate change. Thus, using groundwater level data, which represent aquifer memory and which are broadly available over Mainland France, is a possible way to improve low-flow modelling. To that end, after a first large set of 1,664 catchments, we first gathered a sample of 107 French catchments, each of them being associated with one or several piezometers which are representative of the catchment hydrogeological context. Thereby, this database includes 160 catchment/piezometer pairs. Then, we highlighted the catchment memory phenomenon, by developing and applying a new hydrograph separation method. We studied annual statistics on mean values and extreme events of streamflow and groundwater level time series; through this study, we underlined the relationships between aquifer and catchment memory, while we emphasised the regional differences and the diversity of roles played by aquifers in surface hydrology. Afterwards, we developed and validated a lumped conceptual hydrological model, able to simulate both streamflow and groundwater level, by adapting the structure of an existing hydrological model and by proposing a new calibration strategy. Finally, we evaluated this model as a low-flow forecasting tool and we tried to improve its performance by performing full assimilation of observed data into the model. The originality of our work lies in using both streamflow and groundwater level data for surface hydrology, in an inter-disciplinary approach that was applied to a large number of catchments with varied contexts. [/read]
  • 12 August 2021, Maria-Helena Ramos is invited to talk about « The quality and value of hydrological forecasts and predictions » in the Topical Webinar Series hosted by the Core Modelling and Forecasting Team of the Global Water Futures program of the University of Saskatchewan. Recording available here.
  • 18 July  2021, Vazken Andréassian coordinates the contribution « Prévisions, climat, gestion des risques… Les crues mortelles d’Allemagne et de Belgique en sept questions », published by « The Conversation » (here)
  • 15 July 2021, Maria-Helena Ramos co-wrote the synthesis of the « Global Hydrological Workshop 2021″, Online Newsletter Copernicus EMS (here
  • 1 June 2021, 14 h (online): PhD defence of Anthony Lemoine (INRAE Antony/Sorbonne Université), « Impact indicators of hydroclimatic changes on the management of hydropower reservoirs » [in French]. Résumé/abstract
  • 19 May 2021, 16h (online): Seminar by Dr Juliane Mai (University of Waterloo), Application of Parameter Screening to Derive Optimal Initial State Adjustments for Streamflow Forecasting. Post on Twitter.
  • 19 – 30 April 2021: Our researchers are joining vEGU21. You can find here [Participation_ EGU2021] the list of abstracts (vPICOs) of the HYDRO team at Antony, as well as the sessions they organize this year.
  • 19 April 2021, the partners of the project ANR PICS contribute to the News INSU CNRS (MISTRALS research programme): Payrastre, O., O. Caumont, B. Janet, P. Javelle, D. Lague, J-P. Naulin, D. Moncoulon, F. Pons, M-H. Ramos, I. Ruin, Better anticipate Mediterranean flash floods and their impacts, 19 April 2021 [in French].
  • 9 April 2021, 14 h (online): PhD defence of Paul Royer-Gaspard (INRAE Antony/Sorbonne Université), « Improving the robustness of hydrological models in varying climatic conditions » [in French]. Résumé/abstract.
  • 7 April 2021, 11 h (online): Seminar by Laurène Bouaziz (Deltares), Behind the scenes of streamflow model performance.
  • 12 March 2021, 14 h (online): PhD defence of Daniela Peredo (INRAE Antony/Sorbonne Université), « What gains from adapting a hydrological model and using an ensemble forecasting approach for the forecasting of flash floods? » [in French]  [read more= »Read more » less= »Read less »] Flood forecasting plays a fundamental role in anticipating and implementing measuresto protect lives and property. The objective of this thesis is to investigate our ability to improve the simulation and forecasting of major flash flood events in France. First, we analyze the limitations of the lumped hydrological modelling approach, and how the contribution of the semi-distributed hydrological model GRSD, with fine mesh and hourly time step, to improve the simulation of major flood events. We also propose a modification of the structure of the model, in order to make it better suited to reproducing the response of the catchments to high rainfall intensities. Second, we explore the ability of a meteorological ensemble prediction approach, combined with the semi-distributed hydrological model, to better predict flash flood events, the amplitude and the time of occurrence of peak flows, whether in gauged or ungauged basins.[/read]
  • 29 May 2020, 9h (online): PhD defence of Manon Cassagnole (INRAE Antony/AgroParisTech), « Analysis of the link between the quality of hydrological forecasts and their economic value for the hydropower sector » [in French].
  • 6 January 2020: Interview of Vazken Andréassian in the RMC documentary « La science des forces de la nature – Inondations » (in French only)
  • 5 October 2019: Participation of Guillaume Thirel to the fête de la Science at forum des Halles in Paris : « Et si l’Île-de-France était engloutie sous les eaux ? | Guillaume Thirel – Science En Direct »
  • 24 September 2019: Participation of Guillaume Thirel to a EGU HS blog post: « Hydrologists Join Youth-Led #GlobalClimateStrike » 
  • 10 September 2019, 14 h (room Chenu) : Seminar « Water and multidisciplinarity: examples of practical studies ». The HYDRO team welcomes three visiting scientists. They will be presenting the following: Amaury Tilmant (Université Laval, Québec), Analyzing the relationship between statistical scores and the economic performance of probabilistic hydrologic forecasts; Nicolas Avisse (Université Laval, Québec), Quantitative Assessment of Contested Water Uses and Management in the Conflict- Torn Yarmouk Basin; Ilias Pechlivanidis (SMHI, Norrköping, Suède), Large-scale hydrological services: challenges and opportunities for the co-evolution of knowledge (abstracts).
  • 17 August 2019: Radio Interview of Vazken Andréassian regarding the current drought on the RTL morning broadcast: link (between 01:08:45 and 01:09:30) 
  • 5 June 2019, 10 h (room Loing, Antony): Seminar of Laurène Bouaziz, PhD Candidate at Deltares / TU Delft, The Netherlands, « Hydrological modelling of the Meuse River basin ».
  • 18 April 2019, 11 h (room Seine, Antony): Seminar of Céline Cattoën-Gilbert, Hydrological Forecasting Scientist, National Institute of Water & Atmospheric Research Ltd (NIWA), « Forecasting flows, flood and hazards in New Zealand » [read more= »Read more » less= »read less »] Flooding is the most frequent natural disaster in New Zealand. We will present some of NIWA’s work on forecasting flood and hazards, including key aspects and challenges of the development of a Water Model and a national short-term flow forecasting system for New Zealand rivers. The forecast system is updated every 6 hours and produces river flow forecasts at more than 60,000 sub-catchments in the highly diverse New Zealand environment to provide water information required nationally. We will present work towards a methodology to produce ensemble flood forecasts with improved uncertainty representation with convective-permitting ensemble weather forecasts. The first component is a new precipitation forecast calibration and ensemble generation method to post-process deterministic numerical weather predictions. The second component is assessing the impact of perturbed physics weather ensembles based on different weather initial conditions and model configurations. We will also briefly introduce some new developments on a remote sensing system ‘drone flow’ for measuring river flows from the air to collect high resolution data of water depths, velocities, and volumetric flow rate. Using drones enables measurement of flows where existing methods are inadequate or dangerous, such as during floods. Contributors: Cattoën C., Montgomery K., Mari A., Carey-Smith T., Moore S., Measures R., Smart G., Robertson D. E., Bennett J.C, Wang Q.J., Fedaeff N., Shankar U., Biggs H.[/read]
  • 10 January, 14 h (oom Seine, Antony): Seminar of Paulina Lopez-Alarcon, Understanding interstate hydro-political tensions from general patterns to spatio-temporal contextualities.
  • 27 November 2018: PhD defence of Léonard Santos (Irstea Antony), Que peut-on attendre des Super Modèles en hydrologie ? Évaluation d’une approche de combinaison dynamique de modèles pluie-débit. Lieu : AgroParisTech, Paris.
  • 26 November 2018: PhD defence of Cédric Rebolho (Irstea Antony), Modélisation conceptuelle de l’aléa inondation à l’échelle du bassin versant. Lieu : Irstea, 1 rue Pierre-Gilles de Gennes, 92761 Antony, salle Galilée.
  • 6 November: Article on airGRteaching in the valorisation newsletter of Irstea (ft. Olivier Delaigue and Guillaume Thirel). Newsletter (page 3).
  • 26 October: Interventions by Guillaume Thirel during the School for Young Scientists, at the Water Problem Institute in Moscow. Seminar Hydrology of ungauged catchments, Workshop Hydrological modelling with the GR rainfall-runoff models.
  • 15 October: Interview of Guillaume Thirel by CERDD in a small video about the link between water, biodiversity and climate. Video.
  • Sunday 14 October: Participation of the HYDRO team (with Lila Collet, Charles Perrin, Anthony Lemoine, Paul Royer-Gaspard, Guillaume Thirel and Nathalie Touze) to the Fête de la Science at Antony. Demonstration of the water cycle with a model and visualisation of the impact of climate change on floods and droughts with an artistic installation and posters.
  • 9 August: Interview of Lila Collet for the TV news of RTL on drought and flood risk (mp3)
  • 19 June: Presentation and round table live streaming with participation of Guillaume Thirel during a Water and Biodiversity event organised by CERDD Live streaming.
  • 12 June: Live interview of Charles Perrin on BFMTV.
  • 12 June: Interview of Vazken Andréassian in the news on TF1.
  • 22 May, 14 h 30 (room Loing, Antony): Seminar of Thibault Hallouin, University of Dublin: « Utilisation d’un modèle pluie-débit pour l’écohydrologie en Irlande »
  • Sunday 29 April: Interview of Vazken Andréassian in The Conversation: « Jour zéro » : du Cap à São Paulo, les grandes villes face à la pénurie d’eau.  
  • 26 April: Interview of Guillaume Thirel in the News of the Irstea website: Impact du changement climatique sur les affluents français du Rhin : les débits futurs actualisés.  
  • 23 April, 11 h (room Galilée, Antony): Seminar by Keirnan Fowler, researcher at Université of Melbourne ( : « Towards improved rainfall-runoff modelling in changing climate ». [read more= »Lire la suite » less= »Lire moins »] It has been widely shown that rainfall-runoff models often provide poor and biased simulations when applied in changing climate. This seminar will present recent research towards diagnosing and remedying this problem. Using case studies from southern Australia, the underlying causes of poor model performance will be discussed, along with initial research into model structural improvements. It will examine the role of calibration methods in preparing models for changes in climate, and present a systematic framework for model improvement.[/read]
  • 20 April, 14 h (room Seine, Antony): Seminar of Mathilde Chauveau, engineer at BRLi ( : « Estimation de l’hydrologie du bassin du Congo à grande échelle pour la modélisations des impacts techniques de grands projets d’aménagements ».
  • 16 April 2018, 11 h (room Seine, Antony): Seminar of David Robertson (Principal Research Scientist – Water Forecasting Land and Water, CSIRO, Australia), « Toward accurate and reliable 7-day ensemble streamflow forecasts for Australia ».
  • 12 April: Interview of Maria-Helena Ramos on “Games in Geosciences” for  Radio Dutch 1 (recorded at the EGU GA in Vienna, by Rolf Hut). Here.
  • 9 April: Interview of Guillaume Thirel in the News of the Irstea website: Hydrologie de montagne : améliorer la prévision des débits en prenant mieux en compte la neige.
  • 6 April 2018, at 13 h 30 (room Astier, building Esclangon, Campus Jussieu, Paris): Habilitation defence of Maria Helena Ramos: « Quality and value of hydrological ensemble forecasts ». Summary.
  • 5 April, at 11 h (room Seine, Antony): Seminar of Luc Descroix, Senior researcher at IRD, « Changements d’usage des sols, changements climatiques et hydrologie en Afrique de l’Ouest sahélo-soudanienne: paradoxes et contrastes régionaux ».
  • 22 March 2018: Interview of Guillaume Thirel in an article of the Ain Agricole : ZOOM SUR —FONTE DES NEIGES : Quel impact sur les crues de printemps ? 
  • 21 March 2018: Interview of Vazken Andréassian, in « Trois minutes pour la planète » of Radio Classique on the multiplication of water shortages in big cities. 
  • 20 February (room Galilée, Antony): Seminar NIRE (Japon) & Irstea Antony (France) [read more= »Read more » less= »Read less »] The presentations:
    • 9h 10: José Martinez (Irstea): Irstea’s international activities and NIRE/NARO – Irstea MoU
    • 9h 30: Evelyne Talès (Irstea): “eDNA for monitoring fish biodiversity in streams: spatial and temporal evolution”
    • 10 : Noriyuki Koizumi (NIRE/NARO): “Upstream migration monitoring of amphidromous fish using eDNA”
    • 10 h 45: Hocine Hénine (Irstea): “Hydrological modelling and engineering at the scale of agricultural drained catchment”
    • 11 h 15: Ikuo Yoshinaga (NIRE/NARO): “Model analysis of nutrient transport in irrigation and drainage system”
    • 11 h 45: Katsushi Shirahata (NIRE/NARO): “Tidal response method with simple decomposition techniques to estimate aquifer hydraulic properties”
    • 15 h 15: Maria Helena Ramos and Guillaume Thirel (Irstea): “Research activities of the Catchment Hydrology group”.
    • 15 h 45: Takeo Yoshida (NIRE/NARO): “Hydrological observation and modeling at Hydrology and Water Resources Unit , NIRE”
    • 16h 15: Susumu Miyazu (NIRE/NARO): “Development of inundation analysis model using radar-derived rainfall”
    • 16h 45: Olivier Chapleur (Irstea): “Improving microbial bioprocesses for waste valorisation with advanced molecular biology tools“[/read]
  • January, media interventions during the River Seine floods: following high precipitations during two months (more than 200 mm), many floods occurred on the River Seine and its tributaries. Researchers of our team answered to several media sollicitations for explaining these phenomena.
  • 12 January 2018: PhD defence of Philippe Riboust (Irstea Antony and UPMC), From snow to streamflow: on a better constraint and representation of snow in models. Venue: Université Pierre et Marie Curie (UPMC), 4 Place Jussieu, 75005 Paris, Amphithéâtre 55B. [read more= »Read more » less= »Read less »] Mountain watersheds have the peculiarity of accumulating precipitations in a solid form and maintaining low flows during winter. This accumulated snow melts during the spring and can cause high river runoff. For hydrologists, the use of a snow model in addition to a hydrological model is required in order to correctly simulate runoff in these watersheds. Snow model parameters are often calibrated on runoff data at the same time as hydrological model parameters. Snow models are thus dependent on the hydrological model they are coupled with, which can promote higher performance on runoff simulation at the expense of snow state simulations performances.
    The objective of this thesis is to make the calibration of the snow model more independent from the calibration of the hydrological model, while remaining easily usable for runoff forecasting. This also means that the model should not be costly computationally speaking and should use simple forcing variables. Calibrating snow model on observed snow data would on one hand improve the robustness of the snow model parameters and on the other hand improve the snowpack modelling. A snow model with the ability of explicitly simulating the state of the snowpack would help to bring better management of water resources, whether for forecasting (management of dams, high and low flows) or climate change impacts studies (better temporal and spatial extrapolation).
    Several studies have shown that the use of snow cover area observations from MODIS remote sensing data for snow model calibration gives better snow simulation. We modified the semi-distributed CemaNeige degree-day model so that it can explicitly simulate the watershed snow cover area. This modification coupled with the calibration of the model on snow cover area data and on river runoff data significantly improved the simulation of the snow cover area by the model without significantly deteriorating the runoff performances. We also found that parameters calibrated this way were more robust. However, the spatial scale used by the degree-day model is too large and does not allow comparison with in-situ snow water equivalent measurements.
    In order to simulate a snow water equivalent comparable to in-situ data, it is necessary to distribute the snow model on the watershed. Therefore, we started the development of a new point scale snow model based on the resolution of the mass and the energy balance. The use of identical forcing data as for degree-day models (temperature and precipitation) is the main constrain imposed to the model. Therefore, a radiation model was created to simulate incoming solar and atmospheric radiations from daily temperature range data. This radiation model is able to provide forcing data to a snow model that solves the heat equations within the snowpack by using a spectral representation of the temperature profile. This representation simulates the temperature profile and gradients using fewer state variables than a vertical discretization of the snowpack. The development of the model is not complete, the modeling of the phase change and the evolution of the water content within the snowpack remain to be developed.[/read]
  • 11 January 2018, 15 h (room Seine, Antony): Seminar of Massimiliano Zappa (WSL, Switzerland), HEPS challenges in mountainous areas.
  • Saturday 6 January 2018: Intervention of Vazken Andréassian in an article of France Info on the Seine River flood, Intempéries : la crue de la Seine à Paris « n’est pas du tout exceptionnelle ».
  • 15 December 2017, 11 h 15 (room Seine, Antony): Seminar of Fernando Neves Lima (UFMG, Brésil), Joint calibration of hydrological model and rating curve parameters for flash flood events,
  • 15 December 2017, 10 h 30 (room Seine, Antony): Seminar of Jean-Emmanuel Paturel (IRD, France), Travaux de modélisation en Afrique de l’Ouest
  • 27 October 2017, 11 h (room Loing, Antony): Seminar of Alberto Assis dos Reis (Cemig, Brésil), Ensemble Seasonal Streamflow Forecast for Hydropower in Brazil, . [read more= »Read more » less= »Read less »] The Brazilian electric system is essentially hydrothermal, with a great part of hydraulic generation (near 65%). Streamflow forecasts can be very beneficial to allow early response in extreme climactic events and for a more efficient operation of the hydropower plants. This presentation gives an overview of how hydrological forecasting interacts with hydropower management in Brazil and introduces the study initiated by Cemig, a Brazilian power company headquartered in Belo Horizonte capital of the state of Minas Gerais, on the use of ensemble weather forecasts and the ESP (Ensemble Streamflow Prediction) technique as forcings to the hydrological model operated by Cemig in order to develop a robust seasonal forecasting system. The developments will be conducted within the FEWS-Cemig platform that is already running in operational mode. It will deal with the combination of different sources of gridded observed precipitation to obtain a better estimative of the observed precipitation in Brazil and apply seasonal forecasts to a large group of basins. [/read]
  • 8 October 2017: Participation of Cédric Rebolho to Esprit Sorcier during the Fête de la Science, presentation of a mystery item: video.
  • September 2017: Participation of Guillaume Thirel to the Rock-Head Sciences: A Day in the Geolife Series blog: link.
  • July 2017: Video of Vazken Andréassian, Resilient Cities | Flooding: Exploring Early Warning Systems | Ep#2 | AXA Research Fund: link.
  • 10 juin 2017: Video of Cedric Rebolho, Inondations: que peut la recherche ? Retour sur la crue de la Seine de juin 2016: link.
  • 15 May 2017, 11 h 15: Seminar of Xavier Litrico (LyRE SUEZ). A web based tool for operational real-time flood forecasting using data assimilation to update hydraulic states. [read more= »Read more » less= »Read less »] This presentation describes an operational flood forecasting system set up for the city of Dijon, France. This system assimilates real-time flow data at an hourly time step with the stationary Kalman filter and to update hydraulic states. It uses a semi-distributed hydrologic model to integrate rainfall measurements and forecasts and provide discharge forecasts at several points on the watershed. It also offers powerful data management tools and an elaborated graphical interface available from any computer connected to the Internet. The hydrologic model was calibrated using a semi-distributed approach and its simulation and forecasting performances were analyzed using the Nash-Sutcliffe coefficient, Q-Q plots, and the root-mean-square error as a function of lead time. Its simulation and forecasting performances are analyzed. The performances of the system on a recent flood event are also investigated. [/read]
  • 10 May 2017, 11 : Seminar of Margarita Saft (University of Melbourne). International investigation of climate-runoff response long-term dynamics. [read more= »Read more » less= »Read less »]This talk will present recent results from an empirical investigation into the variability of climate-runoff relationships on interannual to interdecadal timescales. Some catchments are prone to shift their functioning under prolonged change in climatic conditions such as a decade-long drought. The frequency, direction and extent of shifts in climate-streamflow relationship vary between different regions analysed (Europe, North America, Australia), and we discuss what these differences might be related to. [/read]
  • 20 March, 10 : Seminar of Simone Gabellani & Lauro Rossi (CIMA Research Foundation), Research activities at CIMA in hydrometeorology. Irstea Antony. Résumé/Abstract : [read more= »Read more » less= »Read less »] After a short introduction of CIMA the talk will concern: 1) The Dewetra platform aimed at weather-related risk forecasting and monitoring. Dewetra collects and systematizes all data, automatically or manually recorded, and allow to produce value-added elaborations: forecast models, remote and in situ observations are integrated with vulnerability and exposure data to produce risk scenarios in real time. The platform is currently used at national level by forecasters and disaster managing authorities in different countries: Italy, Bolivia, Lebanon, Albania, Caribbean. 2) Flood forecasting and research activities of CIMA in hydrology. In particular, the hydrometeorological chain FloodPROOFS and research activities in data assimilation of satellite soil moisture data will presented. 3) Snow modelling and collaboration with IRSTEA: The scientific collaboration between the two institutes has dealt with research activities in snow modelling and the assimilation of snow-related data. The presentation will mainly focus on the development of a Particle Filter scheme and the resulting performances at different Alpine sites. 4) The Rapid Analysis and Spatialisation and Of Risk (RASOR) platform. It is a multi-hazard risk analysis platform to support the full cycle of disaster management. It provides up-to-date hazard information across floods and geohazards, up-to-date exposure data from known sources and newly-generated EO-based data, and characterised quantitatively their vulnerabilities. [/read]
  • 22 March, 13 h 30 (room Galilée, Antony): PhD defense of Angélica Caseri (Irstea Aix-en-Provence and Irstea Antony), « Contribution of geostatistical conditional simulation to ensemble rainfall nowcasting and flash flood warning ». Résume/abstract.
  • February 2017: Videos of Maria-Helena Ramos on building and evaluating European H2020 projects: first video, second video.
  • 27 February, 10 h 15: Hydrological Seminar. Université Pierre et Marie Curie (UPMC), 4 Place Jussieu, 75005 Paris. Salle de conférence l’UFR Terre Environnement Biodiversité (TEB),  Tour 56-46, 2ème étage
    • Prof. Hubert Savenije, Delft University of Technology, Modelling catchments as living organisms Abstract – [read more= »Read more » less= »Read less »] Catchment-scale hydrological models frequently miss essential characteristics of what determines the functioning of catchments. The most important active agent in catchments is the ecosystem. It manipulates and partitions moisture in a way that it supports the essential functions of survival and productivity: infiltration of water, retention of moisture, mobilization and retention of nutrients, and drainage. Ecosystems do this in the most efficient way, establishing a continuous, ever-evolving feedback loop with the landscape and climatic drivers. In brief, our hydrological system is alive and has a strong capacity to adjust itself to prevailing and changing environmental conditions. Although most models take Newtonian theory at heart, as best they can, what they generally miss is Darwinian theory on how an ecosystem evolves and adjusts its environment to maintain crucial hydrological functions. Through a Darwinian approach, we can determine the root zone storage capacity of ecosystems, as a crucial component of hydrological models, determining the partitioning of fluxes and the conservation of moisture to bridge periods of drought. Another crucial element of physical systems is the evolution of drainage patterns, both on and below the surface. Models that do not account for these patterns are not physical. [/read]
    • Prof. Marco Borga, University of Padova, Integrating hydropower and variable renewable energies: a call for hydrology Abstract – [read more= »Read more » less= »Read less »] One of the main recommendations of the 2015 UN Convention on Climate Change (Paris Agreement) for an energy transition is to use renewable energy sources instead of conventional, usually fossil ones. Integrating hydropower, solar and wind power to balance energy demand, considering at the same time other critically important usages of water, brings new challenges to the hydrological community and new opportunities for better understanding of fundamental hydro-climatic processes. Variable renewable power generation is characterized by a large degree of variability inherited from their driving climate variables. The presentation illustrates a framework for exploring and identifying optimal mixes of energy sources, i.e. obtained with the optimal share for each source. Optimal mixes are being identified and discussed for a number of regions worldwide [/read]
  • 27 February, 13 h 30:  PhD defense of Andrea Ficchi (Irstea Antony), An adaptive hydrological model for multiple time-steps: Diagnostics and improvements based on fluxes consistency. Venue: Université Pierre et Marie Curie (UPMC), 4 Place Jussieu, 75005 Paris, Salle de Conférences de l’UFR TEB (tours 46-56, étage 2). [read more= »Read more » less= »Read less »] This thesis aims at exploring the question of temporal scaling in lumped conceptual hydrological modelling. The main objectives of the thesis are to: (i) study the effects of varying the modelling time step on the performance, parameters and structure of hydrological models; (ii) develop a hydrological model operating at different time steps, from daily to sub-hourly, through a unified, robust and coherent modelling framework at different time scales. Our starting point is the chain of conceptual rainfall-runoff models called ‘GR’, developed at Irstea, and in particular the daily ‘GR4J’ lumped model. The GR4J model will be the baseline model to be effectively downscaled up to sub-hourly time steps following a top-down approach. An hourly adaptation of this model had already been proposed in previous research studies, but some questions on the optimality of the structure at sub-daily time steps were still open. This thesis builds on these previous studies on the hourly model and responds to the operational expectation of improving and adapting the model at multiple sub-daily and sub-hourly time steps that is particularly interesting for flood forecasting applications. For our modelling tests, we built a database of 240 unregulated catchments in metropolitan France, at multiple time steps, from 6-minute to 1 day, using fine time step hydro-climatic datasets available: (i) 6-min rain gauges and higher spatial-density daily reanalysis data for precipitation; (ii) daily temperature data for potential evapotranspiration (making assumptions on sub-daily patterns); (iii) sub-hourly variable time step streamflow data. We investigated the impact of the inputs temporal distribution on model outputs and performance in a flood simulation perspective based on 2400 selected flood events. Then our model evaluation focused on the consistency of model internal fluxes at different time steps, in order to ensure obtaining a satisfactory model performance by a coherent model functioning at multiple time steps. Our model diagnosis led us to identify and test a significant improvement of the model structure at sub-daily time steps based on the complexification of the interception component of the model. Thus, we propose a new version of the model at multiple sub-daily time steps, with the addition of an interception store and a complementary modification to the groundwater exchange function, leading to improved model accuracy and coherence. [/read]
  • 24 February, 11 h (room Galilée, Antony): Seminar of Jean Marçais (Laboratoire Géosciences Rennes). Intégration de données hétérogènes pour modéliser et évaluer l’impact de la morphologie sur la qualité de l’eau. [read more= »Read more » less= »Read less »] My research interests aim at understanding why watersheds respond differently to agricultural diffuse pollution (fertilizer and pesticides). Some landscape properties provide natural advantages to clean up agricultural inputs compared to others. I’m developing first order physically based models which can be potentially coupled with data mining approaches. I’m specialized in hillslope hydrology and my skills are in modeling and data mining. [/read]
  • 5 January, 11 h (room Seine, Antony): Seminar of Dennis Hallema (U.S. Department of Energy/Forest Service, USA). Hydrological modelling of the impacts of forest fires on hundreds of catchments in the USA.
  • 9 December, 11 h: Seminar of Ashish Sharma (Australia), Room Condorcet 1er étage. Estimating design floods in a warming climate – gaps, challenges, and the way forward. [read more= »Read more » less= »Read less »] A lot has been said and written about climate change and how it may make floods more frequent and extreme. In this talk I outline what needs to change in a warmer climate for design floods to increase or decrease, present data based (as opposed to model based) evidence for all the changes till date, and present what I feel is a sensible way design flood estimation should be approached in this new climate we are in. Specifically, I show evidence for clear changes in the spatial and temporal patterns associated with extreme storms, along with an increase in design intensities for shorter duration events. These changes present the clearest evidence till date that design flood magnitudes for urban catchments across the world are increasing, a change that needs to be accepted and factored into our planning guidelines urgently given the implications this has to our existing stormwater infrastructure and society in general [/read]
  • 16 November, 14 h, Room Galilée 1&2: Seminar NIRE (Japon) & Irstea Antony (France) [read more= »Read more » less= »Read less »] Presentations:
    • Coupling of natural and anthropogenic hydrological cycles in rice-dominant watersheds – Takeo YOSHIDA, Ph.D. (Senior Researcher, Institute for Rural Engineering, NARO, NIRE)
    • Water management strategies for hydropower generation at irrigation dams in Japan – Tatsuki UEDA, Ph.D. (Principal Researcher, Institute for Rural Engineering, NARO, NIRE)
    • Global warming impacts of the process to utilize digested slurry from methane fermentation as a fertilizer – Masato NAKAMURA, Ph.D. (Senior Researcher, Institute for Rural Engineering, NARO, NIRE)
    • Research activities of the Artemhys Research Team: Attenuation, Remediation, Transfers and Modeling in HydroSystems – Hocine HENINE (Irstea)
    • Hydrological modelling of changing catchments: lessons from a common testing experiment – Guillaume THIREL (Irstea) [/read]
  • 10 November, 15 h, Room Seine:
    • Seminar of Cuan Petheram (CSIRO, Australia), To irrigate or not to irrigate? That is the question!
    • Seminar of François Anctil (Université Laval, Québec, Canada), ÉVAP : un projet favorisant la modélisation hydrologique avec bilan d’énergie.
    • Seminar of Gaia Piazzi (CIMA, Genova, Italy), Snow multivariable data assimilation for hydrological predictions in mountain areas. [read more= »Read more » less= »Read less »]The seasonal presence of snow on alpine catchments strongly impacts both surface energy balance and water resource. Thus, the knowledge of the snowpack dynamics is of critical importance for several applications, such as water resource management, floods prediction and hydroelectric power production.Several independent data sources provide information about snowpack state: ground-based measurements, satellite data and physical models. Although all these data types are reliable, each of them is affected by specific flaws and errors (respectively dependency on local conditions, sensor biases and limitations, initialization and poor quality forcing  data). Moreover, there are  physical factors that make an exhaustive reconstruction of snow dynamics complicated: snow intermittence in space and time, stratification and slow phenomena like metamorphism processes, uncertainty in snowfall evaluation, wind transportation, etc.Data Assimilation (DA) techniques provide an objective methodology to combine observational and modelled information to obtain the most likely estimate of snowpack state. Indeed, by combining all the available sources of information, the implementation of DA schemes can quantify and reduce the uncertainties of the estimations.This study presents SMASH (Snow Multidata Assimilation System for Hydrology), a multi-layer snow dynamic model, strengthened by a robust multivariable data assimilation algorithm. The model is physically based on mass and energy balances and can be used to reproduce the main physical processes occurring within the snowpack: accumulation, density dynamics, melting, sublimation, radiative balance, heat and mass exchanges. The model is driven by observed forcing meteorological data (air temperature, wind velocity, relative air humidity, precipitation and incident solar radiation) to provide a complete estimate of snowpack state. The implementation of an Ensemble Kalman Filter (EnKF) scheme enables to assimilate simultaneously ground-based and remotely sensed data of different snow-related variables (snow albedo and surface temperature, Snow Water Equivalent from passive microwave sensors and Snow Cover Area).SMASH performance was evaluated in the period June 2012 – December 2013 at the meteorological station of Torgnon (Tellinod, 2 160 msl), located in Aosta Valley, a mountain region in northwestern Italy. The EnKF algorithm was firstly tested by assimilating several ground-based measurements: snow depth, land surface temperature, snow density and albedo. The assimilation of snow observed data revealed an overall considerable enhancement of model predictions with respect to the open loop experiments. A first attempt to integrate also remote sensed information was performed by assimilating the Land Surface Temperature (LST) from METEOSAT Second Generation (MSG), leading to good results. The analysis allowed identifying the snow depth and the snowpack surface temperature as the most impacting variables in the assimilation process. In order to pinpoint an optimal number of ensemble instances, SMASH performances were also quantitatively evaluated by varying the instances amount. Furthermore, the impact of the data assimilation frequency was analyzed by varying the assimilation time step (3h, 6h, 12h, 24h). [/read]
  • 8 November, 14 h: PhD Defense of Carine Poncelet (Irstea Antony), From catchment to parameter: how far can the regionalization of a conceptual hydrological model go? Room Galilée @ Irstea, 1 rue Pierre-Gilles de Gennes, Antony.
  • 20 October, 10 h: Seminar of Fulvia Baratelli (Centre de Géosciences, Mines ParisTech), Modelling of hydric fluxes between rivers and groundwater at the regional scale: application to the Loire basin and to the Seine estuary. Room Galilée 1&2.
  • 10 October, 10 h: Seminar of Kai Gerlinger (HYDRON, Karlsruhe, Germany), Application of the LARSIM hydrological model for operational forecasting of streamflows and for simulation of climate change impacts. Room Galilée 1&2.
  • 4 October, 14 h: Seminar of Ansoumana Bodian (Université Gaston Berger, Saint Louis, Sénégal), Impacts of the variability of climate changes on the water resources of the main river basins of Senegal. Room Seine.
  • 24 June, 11 h: Seminar of Wouter Berghuijs (University of Bristol, UK), Large sample hydrology for understanding catchment similarity. Meeting room in the Monod Building.
  • 4 May, 11 h: Seminar of David Wright (University of Adelaide, Australia), Application of generalised influence diagnostics to assess the impact of objective function choice on hydrological model calibration. Salle Galilée 1&2. [read more= »Read more » less= »Read less »] Abstract: Influential data are those that have a disproportionate impact on model performance, parameters and/or predictions. My presentation will cover two topics: (1) using numerical case-deletion influence diagnostics to compare a selection of objective functions commonly applied in hydrology (i.e. Nash-Sutcliffe efficiency criteria, standard least squares, weighted least squares, logarithmic transformed streamflow and the Kling-Gupta efficiency criteria); and (2) development of computationally efficient generalised analytical influence diagnostics, based on work with Benjamin Renard at IRSTEA Lyon.[/read]
  • 3 May, 11 h: Seminar of Dr Murray Peel (Melbourne School of Engineering, Australia), Long-term streamflow projections: A summary of recent results from the Millennium Drought, Room Galilée 1&2. [read more= »Read more » less= »Read less »]Abstract: The recent Millennium Drought in South-Eastern Australia (1997 – 2009) was a 13-year extended dry period during which unusual catchment responses with significant implications for long-term streamflow projections were observed. In just over half of the catchments investigated a statistically significant downward shift in the long-term annual rainfall-runoff relationship was observed. Here I present a summary of recent results using the Millennium Drought as an observed case study of a prolonged dry period to investigate actual catchment response and hydrologic model performance during the drought. I draw conclusions from these results relevant to future long-term streamflow projections. Bio: Dr Murray Peel is a Senior Research Fellow and ARC Future Fellow in the Department of Infrastructure Engineering at the University of Melbourne. He obtained his PhD (Geography) in 1999 from the University of Melbourne as part of the CRC for Catchment Hydrology. His hydrologic research and consulting activities at the University of Melbourne have produced over 85 publications, including 42 articles in international peer-reviewed journals and 8 book chapters. His research interests include catchment hydrology, hydroclimatology, hydrologic impacts of climate change and land use change, improving techniques for hydrologic prediction under changing conditions and understanding global differences in the inter-annual variability of annual runoff. [/read]
  • 2 May, 11 h: Seminar of Marie-Amélie Boucher (UQAC, Canada), Meteorological ensemble forecasts for hydrology: can we out-perform a sophisticated analog-based system?, Room Galilée 1&2. [read more= »Read more » less= »Read less »] Marie-Amélie Boucher is a Professor at the Department of Applied Sciences at the Université du Québec à Chicoutimi, Canada (more about her research here). Her presentation focuses on hydrological ensemble prediction. For more info, here you can read one of her posts published in the HEPEX Blog. [/read]
  • 29 April, 14 h: PhD Defense of Louise Crochemore (Irstea Antony). Seasonal streamflow forecasting for reservoir management. Room: Amphithéâtre 7, AgroParisTech, 19 avenue du Maine, Paris. [read more= »Read more » less= »Read less »] Abstract: Seasonal forecasts can enhance risk assessment in a variety of applications ranging from multi-purpose reservoir management, drinking water supply and preparedness to droughts. Risk assessment tools, for instance, can benefit from seasonal probabilistic forecasting to support risk-based decision-making. However, the implementation of seasonal forecasts still faces impediments, including the quality of seasonal forecasts and the difficulty to tailor seasonal products to end-users’ needs. This thesis investigates seasonal streamflow forecasting for multi-purpose reservoir management. We first assess the quality of seasonal precipitation and streamflow forecasts in sixteen French catchments. Streamflow forecasting systems are proposed and tested in these catchments, and their potential is illustrated in low-flow and drought risk forecasting. Secondly, seasonal streamflow forecasts are applied in reservoir management. A risk assessment tool is developed to forecast risks of water shortages in the Arzal reservoir, in Brittany, France, and the role of seasonal forecasts for risk-based decision-making is assessed. First, we showed that a bias correction of monthly biases in seasonal precipitation forecasts could increase the reliability of streamflow forecasts and harmonize their performances in the sixteen catchments. We then compared several streamflow forecasting systems, based either on ECMWF seasonal forecasts or on historical streamflows and precipitations. A conditioning of historical data based on precipitation forecasts allowed to take advantage of the reliability of historical data and of the sharpness of meteorological forecasts. The proposed methods provided reliable low-flow forecasts and showed a good ability to forecast drought events. Secondly, a low-flow risk assessment tool was developed for the case of the Arzal reservoir. The seasonal streamflow forecasts used as input to a water balance model of the reservoir allowed us to quantify the risks of water shortages in summer. Lastly, a role-playing game was developed to better understand the role of long-term probabilistic information for decision-making in reservoir management. [/read]
  • 28 April, 14 h: Seminar of Christian Zammit (NIWA, New Zeland), Research activities on Hydrological Processes and Water Resources at NIWA (National Institute of Water and Atmospheric Research), Room Lavoisier – Seine [read more= »Read more » less= »Read less »] Christian Zammit is a hydrologist with a MSc in small scale hydrology (University Joseph Fourier- France) and PhD in Soil Physics (University Joseph Fourier- France). You can read more about his research interests here. He will be at Irstea in Antony on 28 and 29 April 2016. [/read]
  • 13 and 14 April: PhD Days of the Graduate School « Gestion des Ressources Naturelles (GRN) », Mines de Paris (programme) [read more= »Read more » less= »Read less »] Seven PhD candidates of our team are participating to the GRN PhD Days in 2016: Andrea FICCHI (oral presentation), Philippe RIBOUST (oral presentation), Sylvia ASSI (poster), Angélica CASERI (poster), Carine PONCELET (poster), Cédric REBOLHO (poster) and Léonard SANTOS (poster) [/read]
  • 13 April, 10 h: Seminar of Alban de Lavenne (Irstea, Antony), Development of the semi-distributed rainfall-runoff model GRSD, Room Lavoisier – Marne
  • 12 April , 10 h: Seminar of Martyn Clark (NCAR, Boulder, USA), Why do supermodels behave badly?, Room Galilée 1&2 [read more= »Read more » less= »Read less »] Martyn is a scientist in the Hydrometeorological Applications Program (HAP) at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado (see more about his research interests and career here). He recently gave an  interview to the HEPEX blog, which you can read here. He will be at Irstea in Antony from 11 to 13 April 2016. [/read]
  • 12 April, 11 h: Seminar of Léonard Santos (Irstea, Antony), Transferability of the SUMO (SUper MOdel) methodology from climatology to hydrology : example with the conceptual model GR4J, Room Galilée 1&2