- Thursday 9 August: Interview of Lila Collet for the TV news of RTL on drought and flood risk (mp3)
- Tuesday 19 June: Presentation and round table live streaming with participation of Guillaume Thirel during a Water and Biodiversity event organised by CERDD Live streaming.
- Tuesday 12 June: Live interview of Charles Perrin on BFMTV.
- Tuesday 12 June: Interview of Vazken Andréassian in the news on TF1.
- Tuesday 22 May, 14h30, room Loing: 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.
- Thursday 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.
- Monday 23 April, 11h, room Galilée: Seminar by Keirnan Fowler, researcher at Université of Melbourne (https://www.researchgate.net/profile/Keirnan_Fowler) : « Towards improved rainfall-runoff modelling in changing climate ». Read More
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.
- Friday 20 April, 14h, room Seine: Seminar of Mathilde Chauveau, engineer at BRLi (https://brli.brl.fr/) : « Estimation de l’hydrologie du bassin du Congo à grande échelle pour la modélisations des impacts techniques de grands projets d’aménagements ».
- Monday 16 April 2018, at 11h, Room Seine: 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”.
- Thursday 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.
- Monday 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.
- 8 – 13 April 2018: IRSTEA researchers are joining their colleagues from all over the world to present their research at the EGU Annual Assembly in Vienna. You can find here the list of all 18 presentations (orals and posters) of the Hydrology team at Antony. Read More
Additionally, the team contributes to the organisation of scientific sessions: Maria-Helena Ramos is co-convener of the session “HS4.3/AS1.10/NH1.13 – Ensemble hydro-meteorological forecasting and predictive uncertainty estimation”, Guillaume Thirel is main convener of the session “HS2.2.1/CR3.7 – Monitoring and modelling of snow”, and co-convener in the sessions “SC1.19/HS12.4 – Using R in Hydrology” and “EOS16/HS1.14 – Innovation in Geoscience, Hydrology and Engineering Education”, Vazken Andréassian is co-convener of the session “HS2.1.7 – What is a «good» hydrological model for impact study?” Maria-Helena Ramos is also chair of the “Hydrological Forecasting” sub-division for the fourth and last consecutive year. She will be appointed deputy president for the Division on “Hydrological Sciences” during this GA.
- Friday 6 April 2018, at 13h30, room Astier, building Esclangon, Campus Jussieu, Paris : Habilitation defence of Maria Helena Ramos : « Quality and value of hydrological ensemble forecasts ». Summary.
- Thursday 5 April, at 11h, Room Seine: 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”.
- Thursday 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 ?
- Wednesday 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. http://intranet.irstea.fr/interview-de-v-andreassian-sur-radio-classique-sur-les-penuries-deau
- Thursday 8 March 2018 at 11h, Room Marne: Seminar from Amaury Tilmant, professor at Université Laval, Québec, “Optimization of hydroelectric production using exogenous hydrological variables”
- Tuesday 20 February, Salle Galilée 1&2: Séminaire NIRE (Japon) & Irstea Antony (France) Read More
- 9h10: José Martinez (Irstea): Irstea’s international activities and NIRE/NARO – Irstea MoU
- 9h30: Evelyne Talès (Irstea): “eDNA for monitoring fish biodiversity in streams: spatial and temporal evolution”
- 10h00: Noriyuki Koizumi (NIRE/NARO): “Upstream migration monitoring of amphidromous fish using eDNA”
- 10h45: Hocine Hénine (Irstea): “Hydrological modelling and engineering at the scale of agricultural drained catchment”
- 11h15: Ikuo Yoshinaga (NIRE/NARO): “Model analysis of nutrient transport in irrigation and drainage system”
- 11h45: Katsushi Shirahata (NIRE/NARO): “Tidal response method with simple decomposition techniques to estimate aquifer hydraulic properties”
- 15h15: Maria Helena Ramos and Guillaume Thirel (Irstea): “Research activities of the Catchment Hydrology group”.
- 15h45: Takeo Yoshida (NIRE/NARO): “Hydrological observation and modeling at Hydrology and Water Resources Unit , NIRE”
- 16h15: Susumu Miyazu (NIRE/NARO): “Development of inundation analysis model using radar-derived rainfall”
- 16h45: Olivier Chapleur (Irstea): “Improving microbial bioprocesses for waste valorisation with advanced molecular biology tools“
- 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.
- Thursday 25 January: Intervention of Cédric Rebolho in C dans l’air on France 5 : Inondations : 2016…2018 et après ?
- Wednesday 24 January: Intervention of Vazken Andréassian in an article of Le Parisien about the River Seine flood: Montée des eaux : le pic est à venir.
- Tuesday 23 January: Intervention of Vazken Andréassian at the 19.45 of M6 about the River Seine flood: link.
- Tuesday 23 January: Intervention of Vazken Andréassian in an article in 20Minutes about the River Seine flood: Vigicrues: Comment les prévisionnistes étudient-ils en temps réel la montée des eaux?
- Friday 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
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.
- Thursday 11 January 2018, 15h: Seminar of Massimiliano Zappa (WSL, Switzerland), HEPS challenges in mountainous areas, Room Seine, Irstea, Antony.
- 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”.
- Friday 15 December 2017, 11h15: Seminar of Fernando Neves Lima (UFMG, Brésil), Joint calibration of hydrological model and rating curve parameters for flash flood events, Room Seine Irstea Antony
- Friday 15 December 2017, 10h30: Seminar of Jean-Emmanuel Paturel (IRD, France), Travaux de modélisation en Afrique de l’Ouest, Room Seine Irstea Antony.
- Friday 27 October 2017, 11h: Seminar of Alberto Assis dos Reis (Cemig, Brésil), Ensemble Seasonal Streamflow Forecast for Hydropower in Brazil, salle Loing Irstea Antony. Read More
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.
- 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.
- 10-14 July 2017: Irstea researchers are joining their colleagues from around the world to present their recent research achievements at the IAHS conference in Port Elizabeth, South Africa. You can find here a list of their presentations and sessions co-organized.
- 10 juin 2017: Video of Cedric Rebolho, Inondations: que peut la recherche ? Retour sur la crue de la Seine de juin 2016: link.
- Monday 15 May 2017, 11h15: 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
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.
- Wednesday 10 May 2017, 11h00: Seminar of Margarita Saft (University of Melbourne). International investigation of climate-runoff response long-term dynamics. Read More
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.
- 23-28 April 2017: Irstea researchers are joining their colleagues from around the world to present their recent research achievements at the European Geosciences Union General Assembly EGU in Vienna. You can find here the list of the 31 oral, poster and PICO presentations from the members of the Hydrology team at Antony. Additionally, the team participates to the organization of scientific sessions: Maria-Helena Ramos is co-convener at “HS4.3/AS4.36/NH1.12 – Ensemble hydro-meteorological forecasting” and “HS5.10 – Hydrological Sciences and Water Footprint Assessment for monitoring and achieving the Sustainable Development Goals”, Guillaume Thirel is main convener and chair of the session “HS2.2.1 – Mountains and snow: Monitoring and modeling of snow”. Maria-Helena Ramos also contributes to the co-organization of the short course SC52/HS12.5 on Hydrological Forecasting, and is chair of the sub-division on “Hydrological Forecasting” for the third consecutive year.
- Monday 20 March, 10h00: Seminar of Simone Gabellani & Lauro Rossi (CIMA Research Foundation), Research activities at CIMA in hydrometeorology. Irstea Antony. Résumé/Abstract : Read More
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.
- Wednesday 22 March, 13h30: 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”. Venue: Irstea Centre d’Antony, 1 rue Pierre-Gilles de Gennes – ANTONY. Room Galilée. Résume/abstract.
- February 2017: Videos of Maria-Helena Ramos on building and evaluating European H2020 projects: first video, second video.
- Monday 27 February, 10h15: 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
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.
- Prof. Marco Borga, University of Padova, Integrating hydropower and variable renewable energies: a call for hydrology Abstract – Read More
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
- Prof. Hubert Savenije, Delft University of Technology, Modelling catchments as living organisms Abstract – Read More
- Monday 27 February, 13h30: 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
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.
- Friday 24 February, 11h: Seminar of Jean Marçais (Laboratoire Géosciences Rennes), Room Galiléé. Intégration de données hétérogènes pour modéliser et évaluer l’impact de la morphologie sur la qualité de l’eau. Read More
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.
- Thursday 5 January, 11h: Seminar of Dennis Hallema (U.S. Department of Energy/Forest Service, USA), Room Seine. Hydrological modelling of the impacts of forest fires on hundreds of catchments in the USA.
- 12 – 16 December 2016: Researchers from the Hydrology team of Irstea in Antony joined over 24,000 colleagues to present their research at the AGU Annual Assembly in San Francisco Read More
- Poster presented by Guillaume Thirel: H53H-1818: airGR: an R-package suitable for large sample hydrology presenting a suite of lumped hydrological models
- Oral presentation by Maria-Helena Ramos: H51K-04: Seasonal streamflow forecasting: experiences with precipitation bias correction and SPI conditioning to improve performance for hydrological events
- Other presentations as co-authors: H51F-1547: Improving medium-range ensemble streamflow forecasts through statistical post-processing et NH53E-01: The HEPEX Seasonal Streamflow Forecast Intercomparison Project
- Organisation of scientific session by Maria-Helena Ramos: H51K: Advances in Hydrologic Prediction Toward Water Resources Decision Making
- Friday 9 December, 11h: Seminar of Ashish Sharma (Australia), Room Condorcet 1er étage. Estimating design floods in a warming climate – gaps, challenges, and the way forward. Read More
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
- Wednesday 16 November, 14h, Room Galilée 1&2: Seminair NIRE (Japon) & Irstea Antony (France) Read More
- 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)
- Thursday 10 November, 15h, 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
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).
- Tuesday 8 November, 14h: 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.
- Thursday 20 October, 10h: 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.
- Monday 10 October, 10h: 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.
- Tuesday 4 October, 14h: 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.
Friday 24 June, 11h: Seminar of Wouter Berghuijs (University of Bristol, UK), Large sample hydrology for understanding catchment similarity. Meeting room in the Monod Building.
- June, media interventions during the Northern France floods: following high precipitations during 48 h (more than 50 mm and even 100 mm in some areas) on already wet soils, many floods occurred on Seine tributaries (Loing, Yvette, Essonne) and Loire tributaries (Cher). Researchers of our team answered to several media sollicitations for explaining these phenomena. Read More
- 1 June: Charles Perrin, Carina Furusho-Percot, Julie Viatgé and Vazken Andréassian, article in The Conversation, A Paris, les risques de crue sous haute surveillance
- 1 June: Carina Furusho-Percot, article in 20 Minutes, Inondations, quelles conséquences sur les villes et les champs ?
- 1 June: Vazken Andréassian, article in Libération, Crues : “Des cumuls de pluie tels qu’on en voit tous les cinquante ans”
- 1 June: Vazken Andréassian, article in Libération, Inondations : “On sauve les objets à valeur sentimentale”
- 2 June: Vazken Andréassian, article in Le Parisien, L’Ile-de-France noyée par une crue historique
- 3 June: Charles Perrin, article in Sciences et Avenir, La grande crue de 1910, ce n’est pas pour aujourd’hui
- 3 June: Vazken Andréassian, article in Le Figaro, Le réchauffement climatique, un suspect douteux
- 3 June: Vazken Andréassian, article in Orange / AFP, Crue de la Seine, à quoi faut-il s’attendre dans les prochains jours?
- 3 June: Charles Perrin, article in BFMTV, La crue de la Seine et de ses affluents a-t-elle été mal anticipée ?
- 3 June: Charles Perrin, interview for BFMTV, Crue à Paris : Un pic à 6.50 m est attendu dans la nuit de vendredi à samedi
- 3 June: Charles Perrin, article in Le Monde, Pourquoi la crue de la Seine a-t-elle été sous-estimée ?
- 3 June: Vazken Andréassian, article in Journal de l’environnement, Crue de la Seine : des réservoirs remplis pour anticiper la sécheresse
- 3 June: Charles Perrin, article in Le Républicain Lorrain, La grande crue de 1910
- 4 June: Vazken Andréassian, interview for BFMTV, Inondations ; la Seine-et-Marne et l’Eure en vigilance rouge
- 4 June: Vazken Andréassian, article in Le Parisien, “Une réserve secrète sous nos pieds”
- 4 June: Vazken Andréassian, interview forFrance 3 Ile-de-France, 12/13 (at 5:30)
- 5 June: Vazken Andréassian, article in Le Figaro, Inondations : “Avec la décrue, le plus inquiétant, ce sont dégâts causés par les sédiments”
- 6 June: Charles Perrin, article in Le Parisien, Intempéries : et si l’on maîtrisait mieux les eaux ?
- 6 June: Vazken Andréassian, interview for France Inter, Inter Treize (at 13:00)
- 7 June: Charles Perrin, article in l’Humanité, “Rien ne pourra nous protéger d’une crue comme celle de 1910”
- Wednesday 4 May, 11h: 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
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.
- Tuesday 3 May, 11h: 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
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.
- Monday 2 May, 11h: 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
- Friday 29 April, 14h: PhD Defense of Louise Crochemore (Irstea Antony). Seasonal streamflow forecasting for reservoir management. Room: Amphithéâtre 7, AgroParisTech, 19 avenue du Maine, Paris. Read More
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.
- Thursday 28 April, 14h: 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
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.
- 17 to 22 April 2016: Irstea researchers joined 13,650 colleagues from around the world to present their recent research achievements at the European Geosciences Union General Assembly (EGU) in Vienna. Here (EGU2016) you will find the abstracts of 13 oral and posters presentations from the members of the Hydrology team at Antony. Read More
Additionally, Maria-Helena Ramos was co-convener of the session HS4.3/AS4.31/NH1.9 – Ensemble hydro-meteorological forecasting, Guillaume Thirel was co-convener and chair of the session HS2.2.1 – Mountain Hydrology: Monitoring and modeling of snow, and Louise Crochemore was co-convener of the session HS4.8/CL3.10 – Servicing Water Users by forecasting, outlooks and climate projections for water services. Maria-Helena Ramos is also committee chair of the sub-division Hydrological Forecasting for a consecutive year.
- Wednesday 13 and Thursday 14 April: PhD Days of the Graduate School “Gestion des Ressources Naturelles (GRN)”, Mines de Paris (programme) Read More
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)
- Wednesday 13 April, 10h: Seminar of Alban de Lavenne (Irstea, Antony), Development of the semi-distributed rainfall-runoff model GRSD, Room Lavoisier – Marne
- Tuesday 12 April , 10h: Seminar of Martyn Clark (NCAR, Boulder, USA), Why do supermodels behave badly?, Room Galilée 1&2 Read More
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.
- Tuesday 12 April, 11h: 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
- Wednesday 9 December 2015: Interview and mini-conference of Guillaume Thirel during the Solutions COP21 event
- October 2015: Article of Pierre Nicolle in HYDROPLUS: “La modélisation au service de la gestion des étiages“
- Monday 5 October 2015: TV interview of Charles Perrin on Public Sénat TV in “On va plus loin”
- Monday 28 May 2015: Seminar of Mathilde Maquin (Université Paris-Saclay), Mise à l’échelle d’un modèle hydrodynamique de bassin versant, Room Lavoisier – Seine
- Friday 13 May 2015: Seminar of David Wright (The University of Adelaide, Australia), Influential point detection diagnostics in hydrological model calibration, Room Lavoisier – Seine
- Tuesday 5 May 2015: PhD Defense of Laure Lebecherel (Irstea Antony). Sensibilité des calculs hydrologiques à la densité des réseaux de mesure hydrométrique et pluviométrique. Paris, AgroParisTech
- Monday 4 May 2015: Seminar of François Anctil (Université Laval, Quebec, Canada), Quelques expériences en prévision hydrologique d’ensemble, Room Lavoisier – Seine
- Tuesday 20 January 2015: Seminar of Nilo Nascimento (UFMG, Brazil), Estimation des dommages dus aux inondations, Room Lavoisier – Seine
- November 2014: Videos of Louise Crochemore for the DROP project, What was Irstea’s role in the Drop project and 2nd video
- Monday 27 Octobre 2014: Seminars of Takao Masumoto, Masahiro Goto, et Yuichi Hirose (NIRE, Univ. Tsukuba, Japon), Functional Assessment of Irrigation Water Wheels as Regional Resources, A Small Hyropower Project as a Tool for Community-Building Activities, Impact Assessment of Climate Change on Agricultural Water Use and Extremes, Room Lavoisier – Seine
- Monday 13 Octobre 2014: Seminar of Narendra Kumar Tuteja (BoM, Canberra, Australia), Extended Hydrological Predictions services for Australia – progress to date and lessons learnt, Room Lavoisier – Seine
- Tuesday 15 July 2014: Seminar of Fernando Fan (IPH-UFRGS, Brazil), Ensemble streamflow forecasting in large-scale tropical river basins in Brazil, Room Lavoisier – Seine
- Monday 26 May 2014: Seminar of Anders Persson (scientist retired from SMHI, ECMWF and the Met Office, Sweden), We cannot escape probabilities, Room Lavoisier – Seine
- Avril 2014: Video of Louise Crochemore that was awarded with the “Communicate your science!” prize from the EGU 2014, Hydrological Drought Predictions for Reservoir Management: What’s the Use?
- Monday 7 April 2014: PhD Defense of François Bourgin, Comment quantifier l’incertitude prédictive en modélisation hydrologique ? Travail exploratoire sur un grand échantillon de bassins versants. AgroParisTech, Paris
- Monday 24 March 2014: PhD Defense of Florent Lobligeois, Mieux connaitre la distribution spatiale des pluies améliore-t-il la modélisation des crues ? Diagnostic sur 181 bassins versants français. AgroParisTech, Paris
- Novembre 2013: Video of Vazken Andréassian giving a conference on climate change and evolution of water resources at the M2C lab in Rouen.
- July 2013: Video of Carina Furusho on the DROP project, video
- Friday 19 April 2013: PhD Defense of Ioanna Zalachori, Prévisions hydrologiques d’ensemble : développements pour améliorer la qualité des prévisions et estimer leur utilité. AgroParisTech, Paris
- Tuesday 26 March 2013: PhD Defense of Laurent Coron, Les modèles hydrologiques conceptuels sont-ils robustes face à un climat en évolution ? AgroParisTech, Paris
- Monday 25 March 2013: Seminar of François Anctil (Université Laval, Quebec, Canada), Room Lavoisier – Seine
- Thursday 14 February 2013: Seminar of Walter Collischonn (IPH-UFRGS, Brazil), Large-scale hydrologic modelling in South America using remote sensing data, Room Lavoisier – Marne
- Monday 11 February 2013 : Seminar of Luciano Raso (Irstea Montpellier, France), Using Ensemble Forecast in Model Predictive Control (MPC) for operational water management, Room Lavoisier – Seine
- Friday 18 January 2013: PhD Defense of Raji Pushpalatha, Low-flow simulation and forecasting on French river basins: a hydrological modelling approach. AgroParisTech, Paris