PD Dr.-Ing.  Uwe Ehret Uwe Ehret

PD Dr.-Ing. Uwe Ehret

  • KIT Campus Süd

    Institut für Wasser und Gewässerentwicklung

    Lehrstuhl für Hydrologie

    Geb. 10.81

    Otto-Amman-Platz 1

    D-76131 Karlsruhe

Research Interests

  • Application of concepts from Information Theory in Hydrology
    • Information content of hydrological data and models
    • Information flows in hydrological systems
  • Hydrological modeling on the lower mesoscale
    • Coupled water- and energyflows in hydrological systems
    • Data-based hydrological modeling
  • Hydrometeorology
    • Design storms
    • Quantitative Precipitation Estimation (QPE) using weather radar
  • River basin management
    • Operational flood forecasting
    • Quantification of uncertainties

Professional Activities

Invited talks (selected, since 2020)

  • 2023/03: Hydrological planning (and warning) in the face of uncertainty. FURIFLOOD Project meeting at KIT.
  • 2022/04: Das Eifelhochwasser 2021: Ablauf und Einordnung aus hydrologischer und meteorologischer Sicht. 19. Hochwasserschutzforum Verband Region Rhein-Neckar.
  • 2021/12: Modeling hydrological systems by hybrid networks, and the benefits of taking an information perspective. AGU Fall meeting, New Orleans, USA.
  • 2021/11: Be certain about uncertainty - Why knowledge about uncertainty is important, and how information theory can help. University of Strasburg, ITES Lab.
  • 2021/10: Flood Forecasting: A piece of cake with tough nuts. Google Flood Forecasting workshop.
  • 2021/04: Information Theory: A Swiss Army Knife for system characterization, learning and prediction. European Geosciences Union General Assembly 2021, Vienna.
  • 2021/04: Starkregen und Sturzfluten in kleinen Einzugsgebieten – Ursachen, Modelle und Management. Hochwasserschutzforum Verband Region Rhein-Neckar.
  • 2021/04: Earth scientist perspectives on machine learning. CSS Lab Colloquium (RWTH Aachen, University of Stuttgart). Together with J. Cermak.
  • 2021/02: Information Theory – Basics and Applications. EAWAG SIAM seminar.


Community Service (selected, since 2020)

  • since 2022/07: Member of CEDIM steering committee (KIT Center for Disaster Management and Risk Reduc-tion Technology).
  • since 2023/05: Deputy speaker KIT Graduate School 'Computational and Data Science' KCDS.
  • 2023/09: Main organizer of 'International Workshop On Information Theory as a Bridge Across the Geosciences and Modeling Sciences', Schneefernerhaus, Germany.
  • 2023/04: Co-Convener of Session 'Advances in diagnostics, sensitivity, uncertainty analysis, and hypothesis testing of Earth and environmental systems models', General Assembly of the European Geophysical Union, Vienna.
  • 2020/08: Co-Organizer of the 3d International Workshop 'Information Theory and the Earth Sciences', Flagstaff, USA (virtual due to Covid).
  • 2019/10: Co-Organizer EGU Leonardo Topical Conference 'Global change, landscape ageing and the pulse of catchments', Esch-sur-Alzette, Luxembourg.
  • 2019/06: Together with C. Prieto main organizer of 'Summer School on Information Theory in the Earth Sciences', IHCantabria, Santander, Spain.
  • 2019/03: Main organizer 'Tag der Hydrologie', KIT Karlsruhe, Germany.
  • 2014/06 - 2019/08: Editor for Hydrology and Earth System Sciences (HESS): Open Access Journal, Impact Factor 5.15.
  • Project referee for Deutsche Forschungsgemeinschaft (DFG), UK Natural Environment Research Council (NERC), Forschungszentrum Jülich, Technology Foundation the Netherlands (STW).
  • Referee for Hydrology and Earth System Sciences, Water Resources Research, Hydrological Processes, Entropy, Atmosphere, Advances in Meteorology, Journal of Climatology, Natural Hazards and Earth System Sciences, Vadose Zone, Hydrology Research, Urban Water Journal, Meteorologische Zeitschrift, Forum für Hydrologie und Wasserbewirtschaftung.



  • International Association of Hydrological Sciences IAHS
  • European Geosciences Union EGU
  • VDI Working group 'Niederschlagsmessung mit Radar'



  • Since 2023/04: Exploring the Potential of machine learning methods for improving operational hydrological forecasting and prediction (EPOforHydro). Funded by KIT graduate school Computational and Data Science KCDS.
  • Since 2022/11: Untersuchung zur Nutzungserweiterung von Stauanlagen in Baden-Württemberg für das Echtzeit-Management von Hitze, Dürre und Hochwasser (HDH-LUBW). Funded by Landesanstalt für Umwelt Baden-Württemberg.
  • Since 2022/07: Unified diagnostic evaluation of physics-based, data-driven and hybrid hydrolog-ical models based on information theory (UNITE). Funded by DFG.
  • Potential- und Machbarkeitsstudie zur Nutzungserweiterung von Stauanlagen in Baden-Württemberg für das Echtzeit-Management von Hitze, Dürre und Hochwasser (HDH-BaWü). Funded by KIT CEDIM.
  • HYbrid, NETwork-based modelling of HYdrological systems (HY-NET). Funded by KIT-centre MathSEE.
  • KIT Future Fields 'A new TEstbed for Exploring Machine LEarning in Atmospheric Prediction' (TEEMLEAP). Main applicant: Peter Knippertz.
  • Radar-based analysis of severe rainfall events at Landgut Lingental
  • DFG Research unit FOR 1598 'CAOS' (From Catchments as Organized Systems to Models based on Functional Units), phase 2. Project 'Towards consistent predictions of water and energy cycles in intermediate scale catchments'.
  • Analysis and improvement of the flood-warning-system for the Goldersbach river. City of Tübingen.
  • DFG Research unit FOR 1598 'CAOS' (From Catchments as Organized Systems to Models based on Functional Units). Project 'Quantitative Precipitation Estimation (QPE) by exploiting the potential of advanced weather radar observations and data assimilation'.
  • DFG Research unit FOR 1598 'CAOS' (From Catchments as Organized Systems to Models based on Functional Units). Project 'An adaptive process based model framework for water-, energy- and mass cycles in lower mesoscale catch-ments'.
  • Development of a flood-forecasting system for the Bühlot river based on Weather Radar and Micro-Rain-Radar. Flood-protection association Baden-Bühl.
  • Integral development concepts for alpine rivers. Bavarian State Agency for the Environment.
  • Basin-wide coordinated reservoir management for extreme events. Bavarian State Agency for the Environment.



Submitted publications


Peer-reviewed publications in ISI-listed journals

Ehret, U., and P. Dey (2023): Technical note: Complexity–uncertainty curve (c-u-curve) – a method to analyse, classify and compare dynamical systems, Hydrol. Earth Syst. Sci., 27(14), 2591-2605.

Ludwig, P., Ehmele, F., Franca, M. J., Mohr, S., Caldas-Alvarez, A., Daniell, J. E., Ehret, U., Feldmann, H., Hundhausen, M., Knippertz, P., Küpfer, K., Kunz, M., Mühr, B., Pinto, J. G., Quinting, J., Schäfer, A. M., Seidel, F., Wisotzky, C. (2023): A multi-disciplinary analysis of the exceptional flood event of July 2021 in central Europe. Part 2: Historical context and re-lation to climate change, Nat. Hazards Earth Syst. Sci., 23, 1287-1311, 1-42, https://doi.org/10.5194/nhess-23-1287-2023.

Mohr, S., Ehret, U., Kunz, M., Ludwig, P., Caldas-Alvarez, A., Daniell, J. E., Ehmele, F., Feld-mann, H., Franca, M. J., Gattke, C., Hundhausen, M., Knippertz, P., Küpfer, K., Mühr, B., Pinto, J. G., Quinting, J., Schäfer, A. M., Scheibel, M., Seidel, F., and Wisotzky, C. (2023): A multi-disciplinary analysis of the exceptional flood event of July 2021 in central Europe. Part 1: Event description and analysis, Nat. Hazards Earth Syst. Sci., 23, 525-551, https://doi.org/10.5194/nhess-23-525-2023.

Gupta, H. V., Ehsani, M. R., Roy, T., Sans-Fuentes, M. A., Ehret, U., and Behrangi, A. (2021): Computing Accurate Probabilistic Estimates of One-D Entropy from Equiprobable Random Samples. Entropy, 23(6), 740.

Thiesen, S., and Ehret, U. (2021): Assessing local and spatial uncertainty with nonparametric geostatistics. Stochastic Environmental Research and Risk Assessment, 10.1007/s00477-021-02038-5, 2021.

Azmi, E., Ehret, U., Weijs, S. V., Ruddell, B. L., and Perdigão, R. A. P. (2021): Technical note: “Bit by bit”: A practical and general approach for evaluating model computational complexity vs. model performance, Hydrol. Earth Syst. Sci., 25(2), 1103-1115.

Thiesen, S., D. M. Vieira, M. Mälicke, R. Loritz, J. F. Wellmann, and U. Ehret (2020): Histogram via entropy reduction (HER): an information-theoretic alternative for geostatistics, Hydrol. Earth Syst. Sci., 24(9), 4523-4540.

Ehret, U., R. van Pruijssen, M. Bortoli, R. Loritz, E. Azmi, and E. Zehe (2020): Adaptive cluster-ing: reducing the computational costs of distributed (hydrological) modelling by exploiting time-variable similarity among model elements, Hydrol. Earth Syst. Sci., 24(9), 4389-4411.

Perdigão, R. A. P., Ehret, U., Knuth, K. H., and Wang, J. (2020): Debates: Does Information Theory Provide a New Paradigm for Earth Science? Emerging Concepts and Pathways of Information Physics, Water Resources Research, 56(2), 10.1029/2019wr025270.

Loritz, R., Kleidon, A., Jackisch, C., Westhoff, M., Ehret, U., Gupta, H., and Zehe, E. (2019): A topographic index explaining hydrological similarity by accounting for the joint controls of runoff formation, Hydrol. Earth Syst. Sci., 23, 3807-3821, 10.5194/hess-23-3807-2019.

Neuper, M., and Ehret, U. (2019): Quantitative precipitation estimation with weather radar using a data- and information-based approach, Hydrol. Earth Syst. Sci., 23, 3711-3733, 10.5194/hess-23-3711-2019.

Thiesen, S., P. Darscheid, and Ehret, U. (2019): Identifying rainfall-runoff events in discharge time series: a data-driven method based on information theory, Hydrol. Earth Syst. Sci., 23(2), 1015-1034.

Darscheid, P., Guthke, A., and Ehret, U. (2018): A maximum-entropy method to estimate discrete distributions from samples ensuring nonzero probabilities, Entropy, 20, 601, 10.3390/e20080601.

Loritz, R., Gupta, H., Jackisch, C., Westhoff, M., Kleidon, A., Ehret, U., and Zehe, E. (2018): On the dynamic nature of hydrological similarity, Hydrol. Earth Syst. Sci., 22, 3663-3684, 10.5194/hess-22-3663-2018.

Seibert, S. P., Jackisch, C., Ehret, U., Pfister, L., and Zehe, E. (2017): Unravelling abiotic and biotic controls on the seasonal water balance using data-driven dimensionless diagnos-tics, Hydrol. Earth Syst. Sci., 21, 2817-2841, 10.5194/hess-21-2817-2017.

Seibert, S. P., U. Ehret and E. Zehe (2016): Disentangling timing and amplitude errors in streamflow simulations. Hydrol. Earth Syst. Sci. 20 (9), 3745-3763, 10.5194/hess-20-3745-2016.

Bauer, H.-S., T. Schwitalla, V. Wulfmeyer, A. Bakhshaii, U. Ehret, M. Neuper and O. Caumont (2015): Quantitative precipitation estimation based on high-resolution numerical weather prediction and data assimilation with WRF - a performance test. 2015, 10.3402/tellusa.v67.25047.

Zehe, E., U. Ehret, L. Pfister, T. Blume, B. Schröder, M. Westhoff, C. Jackisch, S. J. Schymanski, M. Weiler, K. Schulz, N. Allroggen, J. Tronicke, L. Van Schaik, P. Dietrich, U. Scherer, J. Eccard, V. Wulfmeyer and A. Kleidon (2014): HESS Opinions: From response units to functional units: a thermodynamic reinterpretation of the HRU concept to link spatial organization and functioning of intermediate scale catchments. Hydrol. Earth Syst. Sci. 18 (11), 4635-4655, 10.5194/hess-18-4635-2014.

Skublics, D., S. P. Seibert and U. Ehret (2014): Abbildung der Hochwasserretention durch hyd-rologische und hydrodynamische Modelle unter unterschiedlichen Randbedingungen. Hy-drologie und Wasserbewirtschaftung 58 (3), 178-189, 10.5675/HyWa_2014,3_2.

Seibert, S. P., D. Skublics and U. Ehret (2014): The potential of coordinated reservoir operation for flood mitigation in large basins - A case study on the Bavarian Danube using coupled hydrological-hydrodynamic models. Journal of Hydrology 517 (0), 1128-1144, http://dx.doi.org/10.1016/j.jhydrol.2014.06.048.

Crochemore, L., C. Perrin, V. Andréassian, U. Ehret, S. P. Seibert, S. Grimaldi, H. Gupta and J.-E. Paturel (2014): Comparing expert judgement and numerical criteria for hydrograph evaluation. Hydrological Sciences Journal 60 (3), 402-423, 10.1080/02626667.2014.903331.

Ehret, U., H. V. Gupta, M. Sivapalan, S. V. Weijs, S. J. Schymanski, G. Blöschl, A. N. Gelfan, C. Harman, A. Kleidon, T. A. Bogaard, D. Wang, T. Wagener, U. Scherer, E. Zehe, M. F. P. Bierkens, G. Di Baldassarre, J. Parajka, L. P. H. Van Beek, A. Van Griensven, M. C. Westhoff and H. C. Winsemius (2014): Advancing catchment hydrology to deal with pre-dictions under change. Hydrol. Earth Syst. Sci. 18 (2), 649-671, 10.5194/hess-18-649-2014.

Zehe, E., U. Ehret, T. Blume, A. Kleidon, U. Scherer and M. Westhoff (2013): A thermodynamic approach to link self-organization, preferential flow and rainfall-runoff behaviour. Hydrol. Earth Syst. Sci. 17 (11), 4297-4322, 10.5194/hess-17-4297-2013.

Hrachowitz, M., H. H. G. Savenije, G. Blöschl, J. J. Mcdonnell, M. Sivapalan, J. W. Pomeroy, B. Arheimer, T. Blume, M. P. Clark, U. Ehret, F. Fenicia, J. E. Freer, A. Gelfan, H. V. Gup-ta, D. A. Hughes, R. W. Hut, A. Montanari, S. Pande, D. Tetzlaff, P. A. Troch, S. Uhlen-brook, T. Wagener, H. C. Winsemius, R. A. Woods, E. Zehe and C. Cudennec (2013): A decade of Predictions in Ungauged Basins (PUB)—a review. Hydrological Sciences Jour-nal, 1-58, 10.1080/02626667.2013.803183.

Kleidon, A., E. Zehe, U. Ehret and U. Scherer (2013): Thermodynamics, maximum power, and the dynamics of preferential river flow structures at the continental scale. Hydrol. Earth Syst. Sci. 17 (1), 225-251, 10.5194/hess-17-225-2013.

McIntyre, N., Ballard, C., Bruen, M., Bulygina, N., Buytaert, W., Cluckie, I., Dunn, S., Ehret, U., Ewen, J., Gelfan, A., Hess, T., Hughes, D., Jackson, B., Kjeldsen, T., Merz, R., Park, J., O’Connell, E., O’Donnell, G., Oudin, L., Todini, E., Wagener, T. and Wheater, H. (2012): Modelling the hydrological impacts of rural land use change. Hydrology Research, in press.

Ehret, U., E. Zehe, V. Wulfmeyer, K. Warrach-Sagi and J. Liebert (2012): HESS Opinions "Should we apply bias correction to global and regional climate model data?" Hydrol. Earth Syst. Sci. 16 (9), 3391-3404, 10.5194/hess-16-3391-2012.

Ruiz-Villanueva, V., Borga, M., Zoccatelli, D., Marchi, L., Gaume, E., Ehret, U. and E. Zehe (2011): Extreme runoff response to short-duration convective rainfall in South-West Germany. Submitted 10/2011 to Hydrology and Earth System Sciences.

Ehret, U. (2011): Evaluation of operational weather forecasts: Applicability for flood forecasting in alpine Bavaria. Meteorologische Zeitschrift 20 (4), 373-381.Ehret, U., Zehe, E. (2011): Series distance - an intuitive metric to quantify hydrograph similarity in terms of occurrence, amplitude and timing of hydrological events. Hydrology and Earth System Sciences 15 (3), 877-896, 10.5194/hess-15-877-2011.

Ehret, U. (2010): Convergence Index: a new performance measure for the temporal stability of operational rainfall forecasts. Meteorologische Zeitschrift 19 (5), 441-451.

Ranzi, R., Bacchi, B., Ceppi, A., Cislaghi, M., Ehret, U., Jaun, S., Marx, A., Hegg, C. and M. Zappa (2009): Real-time demonstration of hydrological ensemble forecasts in map d-phase. Houille Blanche-Revue Internationale De L Eau (5), 95-104, 10.1051/lhb/2009061.


Peer-reviewed publications

Azmi, E., M. Strobl, R. van Pruijssen, U. Ehret, J. Meyer, and A. Streit (2020): Evolutionary Approach of Clustering to Optimize Hydrological Simulations, in: Computational Science and Its Applications – ICCSA 2020, Cham, 2020, 617-633, Springer International Publishing, Cham.

Azmi, E., U. Ehret, J. Meyer, R. van Pruijssen, A. Streit, and M. Strobl (2019): Clustering as Approximation Method to Optimize Hydrological Simulations, in Euro-Par 2019: Parallel Processing – 25th International Conference on Parallel and Distributed Computing, Göttingen, Germany, August 26–30, 2019, Proceedings. Ed.: R. Yahyapour. Ed.: R. Yahyapour, edit-ed, pp. 256-269, Springer International Publishing, Cham.

Villinger, F., U. Ehret, M. Neuper, J. Ihringer and H. Gysi (2017): Influence of rainfall spatial heterogeneity on flood peaks: Investigations with weather radar. KW Korrespondenz Was-serwirtschaft, 11/17 693-698, DOI 10.3243/kwe2017.11.005.

Kleidon, A., E. Zehe, U. Ehret and U. Scherer (2013): Maximum Power Limits, Dissipative Structures, and Planetary Interactions. in: Beyond the Second Law: Entropy Production and Non-equilibrium Systems, 2014 edition (November 30, 2013) ed., edited by: Dewar, R. C., Lineweaver, C. H., Niven, R. K., and Regenauer-Lieb, K., Understanding Complex Systems, Springer, 400 pages.

Skublics, D., S.P. Seibert and U. Ehret (2013): Abbildung der Hochwasserretention durch hydrologische und hydrodynamische Modelle unter unterschiedlichen Randbedingungen-Sensitivitätsanalyse am Donauabschnitt zwischen Neu-Ulm und Donauwörth", accepted, Hydrologie und Wasserbewirtschaftung.

Ehret, U., E. Zehe, V. Wulfmeyer, K. Warrach-Sagi and J. Liebert (2013): Sollten wir Bias-Korrekturverfahren auf Ergebnisse globaler und regionaler Klimamodelle anwenden? Forum für Hydrologie und Wasserbewirtschaftung 33.13, 175-188, ISBN 978-3-944328-02-7.

Haag, I., U. Ehret, N. Demuth and K. Moritz (2013): ProFoUnD - Ein Werkzeug zur statistischen Analyse von Abfluss- und Wasserstandvorhersagen und zur Ermittlung von Vorhersageunsicherheiten. Forum für Hydrologie und Wasserbewirtschaftung 33.13, 93-104, ISBN 978-3-944328-02-7.

Ehret, U. (2012): (Un-)sicherheiten in der hydrologischen Modellierung und Vorhersage. KW - Korrespondenz Wasserwirtschaft 6, 316-321, 10.3243/kwe2012.06.002.

Ehret, U., J. Götzinger, A. Bárdossy and G. G. S. Pegram (2008): Radar-based flood forecasting in small catchments, exemplified by the Goldersbach catchment, Germany. Interna-tional Journal River Basin Management 6 (4), 323-329.

Ehret, U. (2003): Rainfall and Flood Nowcasting in Small Catchments using Weather Radar. Mitteilungen / Institut für Wasserbau, Universität Stuttgart: H. 121 Stuttgart: Institut für Wasserbau, Universität Stuttgart. 


Other publications

Ehret, U., M. Frank, and A. Hühnerfuß (2023): KCDS: Die Graduiertenschule Computational and Data Science am KIT, Mitteilungen der Deutschen Mathematiker-Vereinigung, 31(2), 110-112.

Prieto, C., U. Ehret, and G. Nearing (2018): Using information theory in Earth sciences, Eos, 99, https://doi.org/10.1029/2018EO107389. Published on 10 October 2018.

Ehret, U., T. Schwitalla, M. Neuper, H. S. Bauer, A. Bakhshaii-Shahrbabaki and V. Wulfmeyer (2013): Neue Entwicklungen bei der radarbasierten quantitativen Niederschlagsschätzung. KRdL Expertenforum 'Wetterradar - Anwendungen und neue Entwicklungen'. Bonn, KrDL im VDI und DIN. 47: 101 - 110, ISBN 978-3-931384-78-4.

Laurent, S., U. Ehret, I. Meyer, K. Moritz and A. Vogelbacher (2010): Dealing with Uncertainty of Hydrological Forecasts in the Bavarian Danube Catchment. Hydrological Processes of the Danube River Basin. M. Brilly, Springer.

Ehret, U. and T. Schmidt (2005): Operationelle Hochwasservorhersage in Bayern am Beispiel des Illerhochwassers im Januar 2004. DWA Landesverband Bayern Mitglieder-Rundbrief (1), 31-33.

Ehret, U., Bárdossy, A. (2002): Hochwasser - Staatsfeind Nr. 1. Wechselwirkungen, Jahrbuch aus Lehre und Forschung der Universität Stuttgart, 2002, pp. 52-61, Selbstverlag Universität Stuttgart.


Academic career

03/92 – 08/96        University of Applied Sciences Stuttgart

  • Civil Engineering
  • Thesis: 'Space-time rainfall modelling in the Aller catchment under consideration of climate change effects'

10/96 – 05/98        University of Stuttgart

  •  Civil Engineering. Major: Water Resources Management and Hydromechanics
  •  Thesis: 'Space-time rainfall modelling in the Aller catchment under consideration of climate change effects'

09/97 – 04/98        University of Waterloo (Canada): Exchange studies. Major: 'Environmental Engineering'

06/98 – 09/02        University of Stuttgart

  • Phd (Prof. Bárdossy, Institute for Modelling Hydraulic and Environmental Systems)
  • PhD thesis: 'Rainfall and Flood Nowcasting in Small Catchments Using Weather Radar'

02/22         Karlsruhe Institute of Technology KIT: Habilitation 'An information view on Hydrology'.

Professional career

06/98 – 09/02        University of Stuttgart, Institute for Modelling Hydraulic and Environmental Systems

  • Junior Researcher, PhD student

11/02 – 10/08        Water Management Agency Kempten

  • Head of the Flood Forecasting Center Iller/Lech

11/08 – 02/11        TU München, Department of Hydrology and River Basin Management

  • Senior Researcher, Deputy Head

since 03/11              KIT Karlsruhe, Institut für Wasser und Gewässerentwicklung, Bereich Hydrologie

  • Senior Researcher, Deputy Head
  • since 08/15: KIT Associate Fellow