EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Linking the dynamic expansion and contraction of stream networks to changes in water storage and water quality in a pre-Alpine catchment

Izabela Bujak1,2, Andrea Rinaldo1,3, Ilja van Meerveld4, Florian Käslin2, and Jana von Freyberg1,2,5
Izabela Bujak et al.
  • 1EPF Lausanne, School of Architecture, Civil and Environmental Engineering, Lausanne, Switzerland
  • 2Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Mountain Hydrology and Mass Movements, Birmensdorf, Switzerland
  • 3Università di Padova, Department of Civil, Environmental and Architectural Engineering (DICEA), Padova, Italy
  • 4University of Zurich, Department of Geography, Zurich, Switzerland
  • 5ETH Zurich, Department of Environmental Systems Science, Zurich, Switzerland

Many headwater catchments are characterized by temporary streams that flow only seasonally or during rainfall events. As a result, the network of flowing streams is a dynamic system that periodically expands and contracts. This dynamic is likely to affect water flow and composition: the expansion of the stream network enhances the hydrologic connectivity of hillslopes to the streams, which facilitates shorter transit times. Also, the onset of flow in previously dry streambeds can cause flushing of sediments and nutrients. However, our knowledge of the relationships between flowing stream network dynamics and water quantity and quality in headwater catchments is still limited because experimental data remain sparse.

Within the TempAqua project we investigate the processes that drive stream network dynamics by relating measurements of stream network geometry to changes in catchment water storage and stream water quality. For this, we monitored the flow state, discharge, groundwater levels, soil moisture, and precipitation in three (3-7 ha) headwater catchments in the northern Swiss pre-Alps (Alptal catchment) in summer and fall 2020 using a wireless sensor network. To obtain high-resolution data of the dynamic stream network, we did multiple mapping surveys using a self-developed mobile phone application. Moreover, we sampled streamwater and precipitation at an hourly resolution during rainfall events at multiple locations to quantify the short-term changes in water quality when the stream network expands. We will present our research activities in the Alptal catchment and discuss the initial results obtained from the combined monitoring of the flowing stream network and hydrometric and hydrochemical variables.

How to cite: Bujak, I., Rinaldo, A., van Meerveld, I., Käslin, F., and von Freyberg, J.: Linking the dynamic expansion and contraction of stream networks to changes in water storage and water quality in a pre-Alpine catchment, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10767,, 2021.

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