Subsurface Stormflow: A well-recognized but still challenging process in catchment hydrology research

• Applicant: Professor Dr. Peter Chifflard
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management
• Term: from 2016 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 299961754

Subsurface stormflow (SSF) is a well-recognized and important runoff generation process in mountainous catchments in humid climates. Since the 1970s research studies which investigate the generation of subsurface stormflow have increased significantly. Although these studies resulted in numerous publications, nevertheless, subsurface stormflow is still a challenging runoff generation process in catchment hydrology. It is still unclear which factors are primarily controlling the temporal and spatial variability of subsurface stormflow and how this can be parameterized in rainfall-runoff models. To fill this research gap the scientific network, Subsurface Stormflow. A well-recognized drology research, will be initiated to discuss current issues concerning the 1) detection of firstorder controls of SSF, 2) the parameterization of subsurface stormflow in rainfall-runoff models and 3) the calibration and validation of the calculated subsurface stormflow. The network consists of Sophie Bachmair, Theresa Blume, Katja Heller, Luisa Hopp, Ute Wollschläger, Thomas Graeff, Oliver Gronz, Andreas Hartmann, Bernhard Kohl, Christian Reinhardt-Imjela, Martin Reiss, Michael Rinderer and Peter Chifflard (PI). Together they will critically reflect above-mentioned current issues and will define research deficits as basis for a future research project which will be realized by the establishment of a research unit proposed to the German Research Foundation. The work program of the network will be performed in six workshops, each will last 3 days. Workshops will be organized as problem-solving moderated meetings, where decisions will be made in separate small groups and presented, discussed and documented in the entire joint group afterwards. The results of the discussions will lead to the formulation of hypotheses as the basis for the intended project proposal. During the first four workshops the following topics will be discussed: 1) Subsurface Stormflow: Where? When? Why? 2) Detection of first-order controls. 3) (Pedo-) Hydrological model concepts. 4) Calibration and validation approaches. The outstanding scientists Nicola Fohrer, Ilja van Meerveld, Doerthe Tetzlaff, AxelBronstert, Olaf Kolditz, Gunnar Lischeid, Brian McGlynn and Markus Weiler will actively participate at the first four workshops and agreed to give essential contributions to the network by raising fundamental questions and leading specific discussions. In the fifth and the sixth workshop the draft proposal will be created and finalized. The six workshops will be organized at the institutes of the members (Univ. Marburg, Trier, Dresden, Durham (USA), UFZ Leipzig and BfW Innsbruck) including field trips to experimental catchments where SSF generation is well investigated. The network will have close cooperation with Markus Casper, Jan Fleckenstein, Arno Kleber, Gerhard Markart, Frido Reinstorf, Hans-Jürgen Vogel, Harald Zeppund Erwin Zehe.

• DFG Programme: Scientific Networks