Guillaume Thirel

Scientist, Research associate in Hydrology

Skill area

Hydrological modelling

Hydrological ensemble forecasting

Data assimilation

Climate change impact


Snowmelt modelling

Remote sensing data


Postdoctorat :

2018 - ongoing: Gaia Piazzi: assimilation of streamflow data in a semi-distributed hydrological forecasting model (co-supervision by C. Perrin).

2018 - ongoing: Lila Collet: Estimation of the hydrological impacts of climate changes and definition of adaptation strategies.

2015 - 2018: Alban de Lavenne: Towards a hydrological modelling taking into account the blue and green water components of water resources (co-supervision by Vazken Andréassian, Charles Perrin and Maria Helena Ramos). Related article: de Lavenne et al. (2016).


PhD Theses:

2019 - ongoing: Thibault Lemaitre-Basset (co-supervision by Ludovic Oudin, Sorbonne Université and Lila Collet): Climate change and water management: Transposability of regional adaptation strategies at the national scale. Funding: GRNE doctoral school fellowship.

2017 - ongoing: Paul Royer-Gaspard (AgroParisTech, main supervision by Vazken Andréassian): Towards climatically-robust hydrological models for water and climate change impact assessment. Funding: JPI-ERA4CS / ANR AQUACLEW project.

2016 - ongoing: Manon Cassagnole (AgroParisTech, main supervision by Maria Helena Ramos): Analysis of the link between the quality of hydrological forecasts and their economic value: case study of the hydropower sector. Funding: H2020 IMPREX project.

2016 - 2017: Visiting PhD Gaia Piazzi (Cima Research Foundation, Italie, encadrement Simone Gabellani): Estimation of Snow Water Equivalent using Data Assimilation. Related article: Piazzi et al. (2018).

2015 - ongoing: Léonard Santos (AgroParisTech): Hydrological model coupling: the 'SUper MOdels' approach (SUMOs). Funding: Irstea fellowship. Related articles: Santos et al. (2018) and Santos et al. (2018).

2014 - 2018: Philippe Riboust (AgroParisTech, co-supervision Nicolas Le Moine and Pierre Ribstein, UPMC): From snow to streamflow: on the interest of a better constraint and representation of snow in model. PhD thesis, Irstea (Antony) and UPMC (Paris), 339 pp. Funding: GRNE doctoral school fellowship. Related articles: Riboust et al. (2018) and Parajka et al. (2018).


M.Sc. or equivalent:

2019: Master thesis, Thibault Lemaitre-Basset (Sorbonne Université Sciences). Impact of climate change and uncertainty analysis on streamflows of a French basin. Main supervision Lila Collet, Collaboration with Juraj Parajka et Alberto Viglione (TU Wien). 

2019: Master thesis, Paul Astagneau (PolyTech Sorbonne). Comparison of hydrological modelling R packages. Co-supervision Olivier Delaigue, Collaboration with Juraj Parajka et Alberto Viglione (TU Wien). 

2018 - 2019: Master thesis, Chiara Cesarini (Univ. Bologna). Hydrogical modelling with airGR over French and Austrian basins. Collaboration with Elena Toth (Univ. Bologna).

2017: Master thesis, Sofia Mata (UPMC Paris VI). airGR, a package for hydrological modelling to improve? Evaluation on many catchments. Main supervision by Olivier Delaigue [PDF].

2016: Master thesis, Jeff Norville (Univ. Paris-Sud XI Orsay): Development of a Verication Scoreboard Utility for Hydrological Forecasts.

2016: Master thesis, Manon Cassagonle (UPMC, Paris VI): Study on the link between the quality of hydrological forecasts and their economic value: case study of the hydropower sector [PDF].

2016: Master 1, Imane Haddadi (Univ. Clermont Ferrand II). Significance statistical tests applied to hydrology. 53p. Co-supervision with Olivier Delaigue. [PDF]

2015: Master thesis, José Manuel Tunqui Neira (UPMC Paris VI). The SUMO (SUper MOdels) for hydrology? 63p. [PDF]

2015: Master thesis, Franck Masclet (UPMC Paris VI). impact study of a hysteresis for the CemaNeige snow module. 50p. [PDF]

2014: Master thesis, Cindy Gosset (Univ. Orsay). Utilisation of snow satellite data for a rainfall-runoff model snow module calibration 63p. [PDF].

2014: Master 1, Madeleine Nicolas (UPMC Paris VI). Impact of climate change on 21st century discharges over France : an assessment with the new IPCC projections (CMIP5) and the Irstea hydrological model (GR). 40p. [PDF].


Ongoing and past projects

Current projects:

AQUACLEW - Advancing Quality of Climate Services for European Water. 2017-2020. JPI-ERA4CS / ANR funding.

CHIMERE 21 - CHIers - MEuse hydrological Regime Evolution in the 21st century. 2017-2019. Agence de l'Eau Rhin-Meuse funding. Project scientific coordinator.

H2020 IMPREX (Research project, European Commission) (2015-2019), IMproving PRedictions and management of hydrological EXtremes.



Past projects:

MOSARH21 - Evolutions des débits futurs sur le bassin du Rhin en contexte de changement climatique. Une évaluation actualisée s’appuyant sur les simulations climatiques issues du 5ème rapport d’évaluation du GIEC (final report). 2015-2018. Agence de l'Eau Rhin-Meuse funding. Project scientific coordinator.

R²D² - Risque, Ressource en eau et gestion Durable de la Durance en 2050 (final report). 2011-2014. GICC funding.

Climaware - Impacts of climate change on water resources management – regional strategies and European view (final report). 2011-2013. IWRM-Net funding.


ORCID: 0000-0002-1444-1830

Scopus: 26533302300






Thirel, G., Gerlinger, K., Perrin, C., Drogue, G., Renard, B., Wagner, J.-P. Quels futurs possibles pour les débits des affluents français du Rhin (Moselle, Sarre, Ill) ? La Houille Blanche, 2019.



Blöschl, G., …, V. Andréassian, …, C. Perrin, …, M.-H. Ramos, …, G. Thirel, … et al. Twenty-three Unsolved Problems in Hydrology (UPH) – a community perspective, Hydrological Sciences Journal, 64:10, 1141-1158, DOI: 10.1080/02626667.2019.1620507, 2019.

Givati, A., Thirel, G., Rosenfeld, D., Paz, D. Climate change impacts on streamflow at the upper Jordan River based on an ensemble of regional climate models, Journal of Hydrology: Regional Studies, 21, Pages 92-109,, 2019.

Iliopoulou, T., Aguilar, C., Arheimer, B., Bermúdez, M., Bezak, N., Ficchì, A., Koutsoyiannis, D., Parajka, J., Polo, M. J., Thirel, G., and Montanari, A.: A large sample analysis of European rivers on seasonal river flow correlation and its physical drivers, Hydrol. Earth Syst. Sci., 23, 73-91,, 2019.

Parajka, J., Bezak, N., Burkhart, J., Holko, L., Hundecha, Y., Jenicek, M., Krajčí, P., Mangini, W., Molnar, P., Riboust, P., Rizzi, J., Sensoy, A., Thirel, G., Viglione, A.. MODIS snowline elevation changes during snowmelt runoff events in Europe. Journal of Hydrology and Hydromechanics, 67, 2019, 101–109, doi: 10.2478/johh-2018-0011, 2019.

Riboust, P., Thirel, G., Le Moine, N., and Ribstein, P., 2019. Revisiting a simple degree-day model for integrating satellite data: implementation of SWE-SCA hystereses. Journal of Hydrology and Hydromechanics, 67, 1, 70–81, DOI: 10.2478/johh-2018-0004, 2019.

Slater, L. J., Thirel, G., Harrigan, S., Delaigue, O., Hurley, A., Khouakhi, A., Prosdocimi, I., Vitolo, C., and Smith, K.: Using R in hydrology: a review of recent developments and future directions, Hydrol. Earth Syst. Sci., 23, 2939-2963,, 2019.

Santos, L., Thirel, G., and Perrin, C.: Technical note: Pitfalls in using log-transformed flows within the KGE criterion, Hydrol. Earth Syst. Sci., 22, 4583-4591,, 2018.

Piazzi, G., Thirel, G., Campo, L., and Gabellani, S., 2018: A particle filter scheme for multivariate data assimilation into a point-scale snowpack model in an Alpine environment, The Cryosphere, 12, 2287-2306,

Santos, L., Thirel, G., and Perrin, C., 2018: State-space representation of a bucket-type rainfall-runoff model: a case study with State-Space GR4 (version 1.0), Geosci. Model Dev., 11, 1591-1605,

Coron, L., Thirel, G., Delaigue, O., Perrin, C., Andréassian, V., 2017: The Suite of Lumped GR Hydrological Models in an R package, Environmental Modelling & Software, 94, 166-171, DOI: 10.1016/j.envsoft.2017.05.002.

de Boer-Euser, T., Bouaziz, L., De Niel, J., Brauer, C., Dewals, B., Drogue, G., Fenicia, F., Grelier, B., Nossent, J., Pereira, F., Savenije, H., Thirel, G., and Willems, P., 2017: Looking beyond general metrics for model comparison – lessons from an international model intercomparison study, Hydrol. Earth Syst. Sci., 21, 423-440, doi:10.5194/hess-21-423-2017.

Dorchies, D., G., Thirel, C., Perrin, J.-C., Bader, R., Thepot, J.-L., Rizzoli, C., Jost, S., Demerliac. Climate change impacts on water resources and reservoir management in the Seine river basin (France), La Houille Blanche, (5), 32-37, 2016, Article.  

Sauquet, E., Y., Arama, E., Blanc-Coutagne, H., Bouscasse, F., Branger, I., Braud, J.-F., Brun, J., Cherel, T., Cipriani, T., Datry, A.,  Ducharne, F., Hendrickx, B., Hingray, F., Krowicki, I., Le Goff, M., Le Lay, C., Magand, F., Malerbe, T., Mathevet, A., Mezghani, C., Monteil, C.,  Perrin, P., Poulhe, A., Rossi, R., Samie, P., Strosser, G., Thirel, F., Tilmant, J.-P., Vidal. Le partage de la ressource en eau sur la Durance en 2050 : vers une évolution du mode de gestion des grands ouvrages duranciens ? La Houille Blanche, (5), 25-31, 2016, Article.

Thirel. G., V. Andréassian, C. Perrin: Editorial: On the need to test hydrological models under changing conditions, Hydrological Sciences Journal, 60:7-8, pages 1165-1173, DOI: 10.1080/02626667.2015.1050027, 2015 - Article.

Thirel, G., V. Andréassian, C. Perrin, J.-N. Audouy, L. Berthet, P. J. Edwards, N. Folton, C. Furusho, A. Kuentz, J. Lerat, G. Lindström, E. Martin, T. Mathevet, R. Merz, J. Parajka, D. Ruelland and J. Vaze. Hydrology under change. An evaluation protocol to investigate how hydrological models deal with changing catchments. Hydrological Sciences Journal, 60:7-8, pages 1184-1199, DOI: 10.1080/02626667.2014.967248, 2015 - Article.

Coustau M., F. Regimbeau, G. Thirel, F. Habets, B. Janet, E. Martin, C. de Saint-Aubin, J.-M. Soubeyroux: Impact of improved meteorological forcing, soil physics and data assimilation on an operational Hydrological Ensemble Forecast System over France, Journal of Hydrology, 525, Pages 781-792, ISSN 0022-1694, DOI: 10.1016/j.jhydrol.2015.04.022, 2015 - Article.

Randrianasolo A., G. Thirel, M.-H. Ramos, E. Martin: Impact of streamflow data assimilation and length of the verification period on the quality of short-term ensemble hydrologic forecasts, Journal of Hydrology, 519, Part D, 2676–2691, DOI: 10.1016/j.jhydrol.2014.09.032, 2014 - Article.

Bourgin F., M.-H. Ramos, G. Thirel and V. Andréassian : Investigating the interactions between data assimilation and post-processing in hydrological ensemble forecasting, Journal of Hydrology, 519, Part D, 2775–2784, DOI: 10.1016/j.jhydrol.2014.07.054, 2014 - Article.

Dorchies D., G. Thirel, M. Jay-Allemand, M. Chauveau, P.-Y. Bourgin, F. Dehay, C. Perrin, C. Jost, J.-L. Rizzoli, S. Demerliac and R. Thépot : Climate change impacts on multi-objective reservoir management: case study on the Seine River basin, France, The International Journal of River Basin Management, 1, 19, DOI: 10.1080/15715124.2013.865636, 2014 - Article.

Thirel G., P. Salamon, P. Burek and M. Kalas: Assimilation of MODIS Snow Cover Area data in a distributed hydrological model using the particle filter, Remote Sensing, 5, no. 11: 5825-5850, DOI: 10.3390/rs5115825, 2013 - Article.

Trinh B.N., J. Thielen-del Pozo and G. Thirel: The Reduction continuous Rank Probability Score for evaluating discharge forecasts from Hydrological Ensemble Prediction Systems, Atmospheric Science Letters, Volume 14, Issue 2, pages 61-65, DOI: 10.1002/asl2.417, April/June 2013 - Article.

Thirel G., C. Notarnicola, M. Kalas, M. Zebisch, T. Schellenberger, A. Tetzlaff, M. Duguay, N. Moelg, P. Burek, and A. de Roo: Assessing the quality of a real-time Snow Cover Area product for hydrological applications, Remote Sensing of Environment, Volume 127, December 2012, Pages 271-287, ISSN 0034-4257, DOI: 10.1016/j.rse.2012.09.006, 2012 - Article.

Thirel G.: Assimilation de débits observés pour des prévisions hydrologiques probabilistes sur la France (Assimilation of observed discharges for hydrological probabilist forecasts over France), La Houille Blanche, N°2-2011, pp. 87-90, DOI: 10.1051/lhb/2011025, 2011 - Article.

Thirel G., E. Martin, J.-F. Mahfouf, S. Massart, S. Ricci, F. Habets: A past discharges assimilation system for ensemble streamflow forecasts over France – Part 1: Description and validation of the assimilation system, Hydrol. Earth Syst. Sci., 14, 1623-1637, doi:10.5194/hess-14-1623-2010, 2010 - Article.

Thirel G., E. Martin, J.-F. Mahfouf, S. Massart, S. Ricci, F. Regimbeau, F. Habets: A past discharge assimilation system for ensemble streamflow forecasts over France – Part 2: Impact on the ensemble streamflow forecasts, Hydrol. Earth Syst. Sci., 14, 1639-1653, doi:10.5194/hess-14-1639-2010, 2010 - Article.

Randrianasolo A., M.H. Ramos, G. Thirel, V. Andréassian, E. Martin: Impact of the use of two different hydrological models on the scores of hydrological ensemble forecasts, Atmospheric Science Letters, Volume 11, Issue 2, pages 100–107, DOI: 10.1002/asl.259, 2010 - Article.

Thirel G., F. Regimbeau, E. Martin, J. Noilhan, F. Habets: Short and medium-range hydrological ensemble forecasts over France, Atmospheric Science Letters, Volume 11, Issue 2, pages 72–77, DOI: 10.1002/asl.254, 2010 - Article.

Martin E., G. Thirel, F. Regimbeau, F. Habets, J. Noilhan, L. Franchistéguy, J.-M. Soubeyroux: Vers une prévision d'ensemble des débits à l'échelle des grands bassins français (Toward an ensemble streamflow prediction system at the scale of major French catchments), La Houille Blanche, N°5, pp. 88-94, DOI: 10.1051/lhb/2009060, 2009 - Article (in French).

Thirel G., F. Rousset-Regimbeau, E. Martin, and F. Habets: On the Impact of Short-Range Meteorological Forecasts for Ensemble Streamflow Predictions, Journal of HydroMeteorology, 9, 1301–1317, DOI: 10.1175/2008JHM959.1, 2008 - Article.


Book chapter

Thirel G. and C. Perrin. Chapitre 19, Impact du changement climatique sur le bassin de l'Orgeval à l'horizon 2050, dans L'observation long terme en environnement, Exemple du bassin versant de l'Orgeval, Editions QUAE, C. Loumagne et G. Tallec, coordinatrices, 2013.


Conference proceedings

Delaigue O., Thirel G., Coron L. & Brigode P., 2018. airGR and airGRteaching: Two Open-Source Tools for Rainfall-Runoff Modeling and Teaching Hydrology. In: HIC 2018. 13th International Conference on Hydroinformatics. EPiC Series in Engineering, (Eds G.L. Loggia, G. Freni, V. Puleo & M.D. Marchis), pp. 541–548. EasyChair. DOI: 10.29007/qsqj.

de Lavenne, A.,  Thirel, G., Andréassian, V., Perrin, C., Ramos, M.-H., 2016. Spatial variability of the parameters of a semi-distributed hydrological model. 7th International Water Resources Management Conference of ICWRS, Bochum, May 2016, Proc. IAHS, 373, 87-94, doi:10.5194/piahs-373-87-2016, 2016.

Andreassian, V., Thirel, G., Margat, J., 2015. Combien de barrages faudrait-il construire en France d'ici 2050 pour compenser l'impact du changement climatique sur les ressources en eau, Les tensions sur l'eau en Europe et dans le bassin méditerranéen : des crises de l'eau d'ici 2050? 7-9 October 2015 - Proceedings.

Sauquet E., Arama Y., Blanc-Coutagne E., Bouscasse H., Branger F., Braud I., Brun J.-F., Cherel J., Cipriani T., Datry T., Ducharne A., Hendrickx F., Hingray B., Krowicki F., Le Goff I., Le Lay M., Magand C., Malerbe F., Mathevet T., Monteil C., Perrin C., Poulhe P., Rossi A., Samie R., Strosser P., Thirel G., Tilmant F., Vidal J.-P., 2015. Le partage de la ressource en eau sur la Durance en 2050 : vers une remise en cause du mode de gestion actuel des grands ouvrages duranciens ? Les tensions sur l'eau en Europe et dans le bassin méditerranéen : des crises de l'eau d'ici 2050? 7-9 Octobre 2015 - Proceedings.

Dorchies, D.,Thirel, G., Perrin, C., Thépot, R., Rizzoli, J.-L. Jost, C., Démerliac, S, 2015. Impact du changement climatique sur la ressource en eau et la gestion des lacs-réservoirs du bassin de la Seine (France), Les tensions sur l'eau en Europe et dans le bassin méditerranéen : des crises de l'eau d'ici 2050? 7-9 Octobre 2015 - Proceedings.

Thirel, G., Perrin, C., Drogue, G., Gerlinger, K., Wagner, J.-P., 2015. Evolutions des débits futurs sur le bassin du Rhin en contexte de changement climatique - Une évaluation actualisée s'appuyant sur les simulations climatiques issues du 5ème rapport d'évaluation du GIEC. Les tensions sur l'eau en Europe et dans le bassin méditerranéen : des crises de l'eau d'ici 2050? 7-9 Octobre 2015 - Proceedings.

Andréassian, V., Margat, J., Thirel, G., and Hubert, P., 2015. What part of natural flow can be considered a "water resource"?, Proc. IAHS, 366, 86-92, doi:10.5194/piahs-366-86-2015.




  • Coron, L., Perrin, C., Delaigue, O., Thirel, G. & Michel, C. (2017). airGR: Suite of GR Hydrological Models for Precipitation-Runoff Modelling. R package version, [ DEVELOPER]
  • Delaigue, O., Coron, L. & Brigode, P. (2017). airGRteaching: Teaching Hydrological Modelling with GR (Shiny Interface Included). R package version [CONTRIBUTOR]

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