Dr. rer. nat. Ralf Loritz

Dr. rer. nat. Ralf Loritz

  • Karlsruher Institut für Technologie (KIT)
    Institut für Wasser und Umwelt
    Bereich Hydrologie
    Kaiserstraße 12
    76131 Karlsruhe

Research Interests

  • Enviromental modeling (physically-based and data-driven)
  • Soil physics and reactive transport
  • Information theory and thermodynamics
  • Hydroinformatics
     

Awards

Award winner of the dissertation price 2020 of the german hydrology society (DHG)

Award winner of the dissertation price 2020 of the Ehrensenator Huber foundation in the field of water research

Projects

Profile-Links

Publications


2026
Scaling and Uncertainty in Soil Moisture Modelling: A Probabilistic Deep Learning Perspective
Bischof, B.; Zehe, E.; Loritz, R.
2026. Hydrological Processes, 40 (8), Art.-Nr.: e70665. doi:10.1002/hyp.70665 Full textFull text of the publication as PDF document
Flood Risk Management Using Representative Hillslopes: Insights From a Historical Flood in Southwest Germany
Manoj J., A.; Villinger, F.; Wienhöfer, J.; Loritz, R.; Zehe, E.
2026. Hydrological Processes, 40 (5). doi:10.1002/hyp.70541 Full textFull text of the publication as PDF document
Is smart sampling worth it? Impact of training data selection on the performance of LSTMs in streamflow prediction
Heudorfer, B.; Loritz, R.
2026. Hydrology Research, 57 (3), 501–517. doi:10.2166/nh.2026.119 Full textFull text of the publication as PDF document
Too much and yet not enough water – Bridging science and decision-making to enhance resilience. HydroExtremes Synthesis Paper
Kunstmann, H.; Mohr, S.; Scherer, U.; Knippertz, P.; Agreiter, M.; Attinger, S.; Barthlott, S.; Bogena, H.; Bouwer, L.; Caviedes-Voullième; Chwala, C.; Brito, M. de; Dietrich, P.; Ehret, U.; Fersch, B.; Franca, M.; Greve, P.; Güntner, A.; Heidenreich, M.; Hendricks-Franssen, H.-J.; Herrmann, F.; Ionita, M.; Kiese, R.; Klassert, C.; Kollet, S.; Kreibich, H.; Kuhlicke, C.; Kunz, M.; Lorenz, C.; Loritz, R.; Ludwig, P.; Marx, A.; Merz, B.; Montzka, C.; Najafi, H.; Neumann, D.; Ossing, F.; Pinto, J.; Sairam, N.; Samaniego, L.; Sanchez-Benitez, A.; Scheidhauer, R.; Schrön, M.; Schweizer, P.-J.; Sielemann, K.; Vorogushyn, S.; Weber, U.
2026. KITopen
Exploring soil moisture dynamics and variability across scales and geological settings using gaussian mixture-long short-term memory networks
Bischof, B.; Klotz, D.; Gupta, H. V.; Zehe, E.; Loritz, R.
2026. Journal of Hydrology, 664 (Pt. A), Article no: 134364. doi:10.1016/j.jhydrol.2025.134364 Full textFull text of the publication as PDF document
2025
Microscale Heterogeneity in Fluid Distribution Patterns During Drainage of a Homogeneous Sand: Neutron Imaging Visualization and Model Limitations
Sternagel, A.; Rajyaguru, A. D.; Trevisan, L.; Loritz, R.; Trtik, P.; Kaestner, A.; Berkowitz, B.; Zehe, E.
2025. Water Resources Research, 61 (9). doi:10.1029/2025WR039963 Full textFull text of the publication as PDF document
KI als Schlüsseltechnologie für die Hochwasservorhersage (Dr. Ralf Loritz)
KI als Schlüsseltechnologie für die Hochwasservorhersage (Dr. Ralf Loritz)
2025. doi:10.5445/IR/1000183778
„Mit KI zum bundesweiten Hochwasservorhersagemodell“- Das KI-HopE-DE-Forschungsprojekt am KIT. - Campus-Report am 22.07.2025
Fuchs, S.; Loritz, R.
2025. doi:10.5445/IR/1000183260
Are Deep Learning Models in Hydrology Entity Aware?
Heudorfer, B.; Gupta, H. V.; Loritz, R.
2025. Geophysical Research Letters, 52 (6), e2024GL113036. doi:10.1029/2024GL113036 Full textFull text of the publication as PDF document
The Unexploited Treasures of Hydrological Observations Beyond Streamflow for Catchment Modeling
Wagner, P. D.; Duethmann, D.; Kiesel, J.; Pool, S.; Hrachowitz, M.; Ceola, S.; Herzog, A.; Houska, T.; Loritz, R.; Spieler, D.; Staudinger, M.; Tarasova, L.; Thober, S.; Fohrer, N.; Tetzlaff, D.; Wagener, T.; Guse, B.
2025. Wiley Interdisciplinary Reviews: Water, 12 (2), Art.-Nr.: e70018. doi:10.1002/wat2.70018 Full textFull text of the publication as PDF document
ML-based Flood Forecasting for Small Catchments in Germany: The KI-HOPE-DE project
Ehret, U.; Loritz, R.; Bondy, J.; Demuth, N.; Dolich, A.; Hollborn, S.; Jia, T.; Keller, J.; Knippertz, P.; Kraft, M.; Lerch, S.; Menzer, I.; Scheibel, M.; Valmassoi, A.
2025. Copernicus. doi:10.5194/ems2025-686 Full textFull text of the publication as PDF document
Can discharge be used to inversely correct precipitation?
Manoj J, A.; Loritz, R.; Gupta, H.; Zehe, E.
2025. Hydrology and Earth System Sciences, 29 (21), 6115–6135. doi:10.5194/hess-29-6115-2025 Full textFull text of the publication as PDF document
Unveiling the limits of deep learning models in hydrological extrapolation tasks
Baste, S.; Klotz, D.; Acuña Espinoza, E.; Bardossy, A.; Loritz, R.
2025. Hydrology and Earth System Sciences, 29 (21), 5871–5891. doi:10.5194/hess-29-5871-2025 Full textFull text of the publication as PDF document
How well do process-based and data-driven hydrological models learn from limited discharge data?
Staudinger, M.; Herzog, A.; Loritz, R.; Houska, T.; Pool, S.; Spieler, D.; Wagner, P. D.; Mai, J.; Kiesel, J.; Thober, S.; Guse, B.; Ehret, U.
2025. Hydrology and Earth System Sciences, 29 (19), 5005–5029. doi:10.5194/hess-29-5005-2025 Full textFull text of the publication as PDF document
Analyzing the generalization capabilities of a hybrid hydrological model for extrapolation to extreme events
Acuña Espinoza, E.; Loritz, R.; Kratzert, F.; Klotz, D.; Gauch, M.; Álvarez Chaves, M.; Ehret, U.
2025. Hydrology and Earth System Sciences, 29 (5), 1277 – 1294. doi:10.5194/hess-29-1277-2025 Full textFull text of the publication as PDF document
Technical note: An approach for handling multiple temporal frequencies with different input dimensions using a single LSTM cell
Acuña Espinoza, E.; Kratzert, F.; Klotz, D.; Gauch, M.; Álvarez Chaves, M.; Loritz, R.; Ehret, U.
2025. Hydrology and Earth System Sciences, 29 (6), 1749–1758. doi:10.5194/hess-29-1749-2025 Full textFull text of the publication as PDF document
2024
CAMELS-DE: hydro-meteorological time series and attributes for 1582 catchments in Germany
Loritz, R.; Dolich, A.; Acuña Espinoza, E.; Ebeling, P.; Guse, B.; Götte, J.; Hassler, S. K.; Hauffe, C.; Heidbüchel, I.; Kiesel, J.; Mälicke, M.; Müller-Thomy, H.; Stölzle, M.; Tarasova, L.
2024. Earth System Science Data, 16 (12), 5625–5642. doi:10.5194/essd-16-5625-2024 Full textFull text of the publication as PDF document
To bucket or not to bucket? Analyzing the performance and interpretability of hybrid hydrological models with dynamic parameterization
Acuña Espinoza, E.; Loritz, R.; Álvarez Chaves, M.; Bäuerle, N.; Ehret, U.
2024. Hydrology and Earth System Sciences, 28 (12), 2705 – 2719. doi:10.5194/hess-28-2705-2024 Full textFull text of the publication as PDF document
Toward Flash Flood Modeling Using Gradient Resolving Representative Hillslopes
Manoj J, A.; Loritz, R.; Villinger, F.; Mälicke, M.; Koopaeidar, M.; Göppert, H.; Zehe, E.
2024. Water Resources Research, 60 (6), Art.: e2023WR036420. doi:10.1029/2023WR036420 Full textFull text of the publication as PDF document
Generalizing Tree–Level Sap Flow Across the European Continent
Loritz, R.; Wu, C. H.; Klotz, D.; Gauch, M.; Kratzert, F.; Bassiouni, M.
2024. Geophysical Research Letters, 51 (6), e2023GL107350. doi:10.1029/2023GL107350 Full textFull text of the publication as PDF document
CAMELS-DE: hydrometeorological time series and attributes for 1582 catchments in Germany
Dolich, A.; Acuña Espinoza, E.; Ebeling, P.; Guse, B.; Götte, J.; Hassler, S.; Hauffe, C.; Kiesel, J.; Heidbüchel, I.; Mälicke, M.; Müller-Thomy, H.; Stölzle, M.; Tarasova, L.; Loritz, R.
2024. doi:10.5281/zenodo.12733967
Untersuchungen zum Potenzial maschineller Lernverfahren für die hydrologische Simulation und Vorhersage am Beispiel von LSTM und LARSIM in Baden-Württemberg
Tanrikulu, O. D.; Ehret, U.; Haag, I.; Loritz, R.; Badde, U.
2024. Hydrologie und Wasserbewirtschaftung, 68 (3), 130–158. doi:10.5675/HyWa_2024.3_1
2023
On how data are partitioned in model development and evaluation: Confronting the elephant in the room to enhance model generalization
Maier, H. R.; Zheng, F.; Gupta, H.; Chen, J.; Mai, J.; Savic, D.; Loritz, R.; Wu, W.; Guo, D.; Bennett, A.; Jakeman, A.; Razavi, S.; Zhao, J.
2023. Environmental Modelling and Software, 167, Art.-Nr.: 105779. doi:10.1016/j.envsoft.2023.105779 Full textFull text of the publication as PDF document
Understanding the hydrological response of a headwater-dominated catchment by analysis of distributed surface–subsurface interactions
Özgen-Xian, I.; Molins, S.; Johnson, R. M.; Xu, Z.; Dwivedi, D.; Loritz, R.; Mital, U.; Ulrich, C.; Yan, Q.; Steefel, C. I.
2023. Scientific Reports, 13 (1), Art.-Nr.: 4669. doi:10.1038/s41598-023-31925-w Full textFull text of the publication as PDF document
2020
Histogram via entropy reduction (HER): an information-theoretic alternative for geostatistics
Thiesen, S.; Vieira, D. M.; Mälicke, M.; Loritz, R.; Wellmann, J. F.; Ehret, U.
2020. Hydrology and earth system sciences, 24 (9), 4523–4540. doi:10.5194/hess-24-4523-2020 Full textFull text of the publication as PDF document
Adaptive clustering: reducing the computational costs of distributed (hydrological) modelling by exploiting time-variable similarity among model elements
Ehret, U.; Pruijssen, R. van; Bortoli, M.; Loritz, R.; Azmi, E.; Zehe, E.
2020. Hydrology and earth system sciences, 24 (9), 4389–4411. doi:10.5194/hess-24-4389-2020 Full textFull text of the publication as PDF document
The role of energy and information in hydrological modeling. PhD dissertation
Loritz, R.
2020. Karlsruher Institut für Technologie (KIT). doi:10.5445/IR/1000105128 Full textFull text of the publication as PDF document
2019
Simulating preferential soil water flow and tracer transport using the Lagrangian Soil Water and Solute Transport Model
Sternagel, A.; Loritz, R.; Wilcke, W.; Zehe, E.
2019. Hydrology and earth system sciences, 23 (10), 4249–4267. doi:10.5194/hess-23-4249-2019 Full textFull text of the publication as PDF document
A topographic index explaining hydrological similarity by accounting for the joint controls of runoff formation
Loritz, R.; Kleidon, A.; Jackisch, C.; Westhoff, M.; Ehret, U.; Gupta, H.; Zehe, E.
2019. Hydrology and earth system sciences, 23 (9), 3807–3821. doi:10.5194/hess-23-3807-2019 Full textFull text of the publication as PDF document
Energy states of soil water – a thermodynamic perspective on soil water dynamics and storage-controlled streamflow generation in different landscapes
Zehe, E.; Loritz, R.; Jackisch, C.; Westhoff, M.; Kleidon, A.; Blume, T.; Hassler, S. K.; Savenije, H. H.
2019. Hydrology and earth system sciences, 23 (2), 971–987. doi:10.5194/hess-23-971-2019 Full textFull text of the publication as PDF document
2018
On the dynamic nature of hydrological similarity
Loritz, R.; Gupta, H.; Jackisch, C.; Westhoff, M.; Kleidon, A.; Ehret, U.; Zehe, E.
2018. Hydrology and earth system sciences, 22 (7), 3663–3684. doi:10.5194/hess-22-3663-2018 Full textFull text of the publication as PDF document
2017
Picturing and modeling catchments by representative hillslopes
Loritz, R.; Hassler, S. K.; Jackisch, C.; Allroggen, N.; Van Schaik, L.; Wienhöfer, J.; Zehe, E.
2017. Hydrology and earth system sciences, 21 (2), 1225–1249. doi:10.5194/hess-21-1225-2017 Full textFull text of the publication as PDF document

Other Publications

 

Conference presentations (Oral)

  • Loritz, R. (Invited, 2021): The role of energy and information in hydrological modelling, Tag der Hydrolgie, Award Lecture, Best german dissertation in Hydrologie 2020

  • Loritz, R. (Invited, 2021): Bridging the gap between bottom-up and top-down models in catchment hydrology, SIAM Conference on Mathematical & Computational Issues in the Geosciences (GS21)

  • Loritz, R., Ehret, U., Neuper, M., and Zehe, E. (2020): The case of distributed rainfall and spatially adaptive modeling, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-6789, https://doi.org/10.5194/egusphere-egu2020-6789

  • Loritz, R. (Invited, 2019): The role of information in hydrological models, Institute for Modelling Hydraulic and Environmental Systems, Stuttgart, Germany

  • Loritz, R., Gupta, H., C. Jackisch, M. Westhoff, A. Kleidon, U. Ehret, and Zehe, E. (2018): On the dynamic nature of hydrological similarity, European Geosciences Union General Assembly, Vienna, Austria

  • Loritz, R. (Invited. 2017): Is there an optimum? How information theory and thermodynamics can help to identify the needed spatial complexity of hydrological models, Workshop - Improving the theoretical underpinnings of hydrologic models - Sopron, Hungary

  • Loritz, R., Neuper, M., Gupta, H., and Zehe, E. (2017): How to handle spatial heterogeneity in hydrological models. European Geosciences Union General Assembly 2017, Vienna. Austria

  • Loritz, R., Hassler, S., Jackisch, C., and Zehe, E. (2016): Picturing and modelling catchments by representative hillslopes. European Geosciences Union General Assembly 2016, Vienna. Austria

 

Conference presentations (Poster) and co-author contributions

  • Presentation - Ehret, U., van Pruijssen, R., Bortoli, M., Loritz, R., Azmi, E., and Zehe, E. (2020): Dynamical clustering: A new approach to make distributed (hydrological) modeling more efficient by dynamically detecting and removing redundant computations, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4772, https://doi.org/10.5194/egusphere-egu2020-4772

  • Poster - Sternagel, A., Loritz, R., Wilcke, W., and Zehe, E. (2020): Simulating preferential soil water flow and reactive solute transport using the Lagrangian Soil Water and Solute Transport Model (LAST), EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7172, https://doi.org/10.5194/egusphere-egu2020-7172

  • Poster - Villinger, F., Loritz, R., and Zehe, E.: Towards a better understanding and modelling of Hortonian overland flow during flash flooding (2020), EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19680, https://doi.org/10.5194/egusphere-egu2020-19680

  • Presentation - Zehe, E., Loritz, R., Ehret, U., Westhoff, M., Kleidon, A., and Mälicke, M. (2018): From catchment organization to dynamic functional similarity, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19632, https://doi.org/10.5194/egusphere-egu2020-19632, 2020

  • Presentation - Jackisch, C., Kleidon, A., Loritz, R., and Zehe, E. (2018): A thermodynamic interpretation of soil water retention and dynamics, EGU General Assembly 2018, Online, 8–13 April 2018

  • Poster - Kiese, N., Loritz, R., Allroggen, N. and Zehe, E. (2017): Influence of bedrock topography on the runoff generation under use of ERT data. Poster presentation. EGU General Assembly 2017. Vienna. Austria

  • Poster - Wienhöfer, J., Loritz, R. and Zehe, E. (2015): Model-based quantification of hydrological similarity at the hillslope scale. European Geosciences Union General Assembly 2015, Vienna. Austria

  • Poster - Loritz, R., Weiler, M. and Seibert, S. (2015): Data mining methods for predicting event runoff coefficients in ungauged basins using static and dynamic characteristics. European Geosciences Union General Assembly 2015, Vienna. Austria