Identification and analysis of process limitations in hydrological model structures

• Applicant: Dr. Björn Guse
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 471280762

Hydrological models often represent complex hydrological systems with simplified model structures. These structures vary among other things in the type and precision of the chosen process representations. That is why simulations of different models not only show differences in model performance, but also reveal deficits in the representation of hydrological processes. To investigate differences and similarities in process representation over different models as well as their limitations, it is necessary to compare different model structures over different catchments.In this scientific network, 15 predominantly young scientists from 12 institutions would like to discuss how a model comparison to detect model deficits could most profitably be done. These are: Björn Guse (PI), Doris Düthmann, Uwe Ehret, Tobias Houska, Jens Kiesel, Ralf Loritz, Lieke Melsen, Tobias Pilz, Sandra Pool, Diana Spieler, Maria Staudinger, Michael Stölzle, Larisa Tarasova, Stephan Thober and Paul Wagner. The aim of the scientific network is to develop a consistent protocol for model structure comparison to identify limitations in process representations. In addition, pilot simulations with three selected and often used models in ten test catchments in Germany will be conducted.Based on several planned discussions and workshops, hypotheses will be developed on how the representation of limiting processes could be improved in models. This work of the scientific network will be summarized for the hydrological community in a joint paper. In addition, a proposal for a research unit will be prepared with the goal to test the developed hypotheses on process limitations in models. To further enhance the analysis of process representations and limitations available data sets for different hydrological processes will be considered.For this purpose, six semi-annual workshops are planned in the following chronological order: (A) model comparison protocol, (B) process and parameter variability, (C) model performance of discharge and individual processes, (D) limitations in process representations, (E) hypotheses for improved process representation and (F) proposal for a research unit.The following well-known international scientists in their respective research topics will be invited to the workshops: (A) Serena Ceola, (B) Thorsten Wagener, (C) Jan Seibert, Frederik Kratzert, (D) Markus Hrachowitz, (E) Dörthe Tetzlaff and (F) Nicola Fohrer.We expect that after three years of intensive exchange and cooperation within the scientific network, significant progress will be made in better understanding process representation in hydrological models and that there will be more clarity which process representations are currently critical and which methods can be used to achieve an improved representation. In this way, this scientific network will make an important contribution to national and international modeling expertise and the broader hydrological community.

• DFG Programme: Scientific Networks