The rapid development of novel analytical instruments resulted in new opportunities for water flow paths estimation and water flux quantification. However, it remains a challenge how to combine the different tracer techniques, ranging from natural tracers (e.g. isotopes of water, carbon and nitrogen, water temperature) to noble gas tracers and other natural and anthropogenic substances in the water, to cover travel times from hours to several decades and centuries throughout hydrological compartments.
Therefore, the goal of the workshop was to foster interdisciplinary discussion about approaches, methods and models to determine water age and transit times throughout the hydrological cycle. 29 scientists from Baden-Württemberg, other regions of Germany and abroad (Switzerland, UK, France, the Netherlands, Luxembourg, Canada) attended the event.
On the first day, methods, approaches and models for the quantification of water age und transit times in the environmental compartments atmosphere, vegetation, unsaturated zone (soil), saturated zone (ground water) and surface water were discussed. Subsequently, strengths and weaknesses of the approaches and models for the different environmental compartments were identified. The focus was on experimental and theoretical approaches.
On the second day, the fluxes at the compartment boundaries were analyzed in a World Café at four tables:
- unsaturated-saturated zone and
- surface water-ground water.
Finally, it was discussed how to develop an appropriate theoretical framework for linking water ages in different compartments and different time scales. After the event, a field trip to the Conventwald research catchment of the University of Freiburg took place.
The workshop was organized by Prof. Markus Weiler (Chair of Hydrology, University of Freiburg).
Prof. Dr. Markus Weiler, Chair of Hydrology, University of Freiburg
Prof. Dr. Werner Aeschbach, Institute of Environmental Physics, Heidelberg University
Prof. Dr. Christiane Werner, Chair of Ecosystem Physiology, University of Freiburg
Prof. Dr. Christiane Stumpp, University of Natural Resources and Life Sciences, Vienna
Based on the results of the workshop, a review paper has been published:
Sprenger et al. (2019): The Demographics of Water: A Review of Water Ages in the Critical Zone
in the journal 'Reviews of Geophysics'
Origin of photos: photos of the workshop (© U. Scherer).