For more than fifty years the Swiss Federal Research Institute WSL has been investigating small torrential catchments in the pre-alpine valley Alptal, located in central Switzerland. In the beginning, the main aim was to improve the understanding of flood formation in such first-order catchments and the role of the forest in this context.
Later, the hydrological research in the Alptal valley focused on ecological and geomorphological questions also. For example, the water quality of the torrents and nitrogen deposition and export of the forest ecosystem have been monitored for decades. In all of these studies a particular attention has been payed to the snow cover in this pre-alpine area. Recently, the Alptal site has become an international hotspot for the investigation of bedload transport, geomorphology, runoff formation and isotope dynamics of torrent catchments.
The extensive new knowledge from the research in the Alptal valley has been presented in national and international publications. The data are available on request available to other researchers.
News ¶
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July 31, 2024: An extremely intense thunderstorm causes one of the highest discharges and bedloads ever measured in the Erlenbach in the last 55 years. The thunderstorm lasts approx. 2.5 hours and has a peak precipitation intensity of 15-25 mm/10 min. The total amount of precipitation at the Erlenhöhe climate station is approx. 50 mm. It is estimated that half of the retention basin is filled with debris and a lot of alluvial wood during this storm. The dam mentioned below is destroyed during the event. Unfortunately, the storm also causes damage and failures in the sediment baskets and the discharge measurement. We are in the process of securing the data and putting the system back into operation.
- 9-July-2024: Upstreams of the Erlenbach discharge and bedload measuring station, a channel clog has recently formed and the supply of bedload to the measuring station has been greatly reduced. This clog is now being monitored using a webcam. This will provide interesting insights into the interaction between fallen wood and bedload.
- 3-July-2024: Izabela Bujak-Ozga (EPFL, WSL) has successfully defended her PhD thesis on the water flow of (intermittent) open channels in the Alptal. The title of her thesis was “Spatiotemporal Dynamics of Flow and Hydrochemistry in Drainage Networks”. Publication 1, Publication 2.
- 1-Feb-2023: Blog about the novel surface runoff measurements of University Zurich (Dept. of Geography) in the upper Studibach catchment in summer 2022 - using a new-developed device called "Bernoulli tube".
- 26-Jan-2023: A new short video about the snow hydrological study of Joschka Geissler (University Freiburg i.Br.) is available here.
- A new dataset with daily Stable Water Isotope concentrations in stream water and precipitation (2015-2019) has been published and is now available for downloading.(see publication Von Freyberg et al., 2022).
Contact ¶
Main coordinator: Manfred Stähli
Sediment measurements: Dieter Rickenmann
NITREX field site: Patrick Schleppi