The working group „Runoff generation and process-oriented modeling” at the Institute of Hydrology,
Faculty of Forestry and Environmental Sciences, University of Freiburg, Germany, is led by
PD Dr. Stefan Uhlenbrook in co-operation with the head of the institute Prof. Dr. Chris Leibundgut.
A variable number of people (between about 5 and 12) work in this group.

Our mission is to improve the general understanding of runoff generation processes at various
temporal and spatial scales and across diverse climates and hydrological settings. In addition, we
work with different hydrological models to enhance our ability to model adequately hydrological
processes. The central goal is the combination of latest experimental data with new and innovative
simulations models to improve the predictions of hydrological variables at gauged and ungauged
sites. This implies the reduction of the prediction uncertainty by incorporating an improved
understanding of the functioning of hydrological processes.

To identify runoff generation processes (flow pathways, source areas and residence times) we
work with different experimental techniques, e.g. classical hydrometric techniques, tracer methods,
geoelectrical techniques etc.. The use of different tracer techniques by applying environmental
isotopes, hydrochemistry and artificial tracers plays a central role. Different statistical techniques of
data analysis are applied to detect major controls of hydrological systems. For the process-based
modeling we developed and improve continuously the hydrological catchment model TAC^D
(tracer aided catchment model, distributed), which aims at predicting hydrological processes at the
landscape scale (hydrological meso-scale: 10¹-10³ km²).