DROUGHT-CH

An NRP61-research project for the early recognition of critical drought and low flow in Switzerland

Droughts have severe consequences for nature and society. This includes impacts on  agriculture, water supply, energy production, building infrastructure, and ecosystems. As droughts can enhance the severity of heatwaves, they also impact human health. Climate models project that events such as the 2003 drought and heatwave will become more frequent in the coming decades in Switzerland. The early recognition of critical drought conditions has large economic and social benefits and is hence essential for drought risk management. The potential of such applications in Switzerland needs to be investigated.

The prediction and characterization of drought events is challenging for several reasons:

1. Droughts are complex phenomena involving numerous interacting climate processes;
2. The sensitivity of regions to droughts depends on several factors, from storage properties and natural resilience to water use and social systems’ vulnerability;
3. Monitoring of relevant variables such as soil moisture – in particular at regional scale – are lacking in many countries, including Switzerland.

The DROUGHT-CH project aims at the characterization and early recognition of critical drought and low-flow conditions in Switzerland, and will provide the scientific basis for the development of an information and early warning platform for drought and low-flow (similar to the upcoming National platform for Natural Hazards, GIN). The project integrates a nature system component (WP2-WP5), dedicated to the improvement of the modelling, observation, forecast, and analysis of drought and low-flow characteristics in Switzerland, with a use and social system component, dedicated to the identification of the needs of end users, stakeholders and decision makers. Both components will interact and jointly provide the basis for the development of the information and early warning platform, which will be available as a prototype by the end of the project.

Research questions:

• How sensitive to drought and low flow are Swiss water systems?
• Where and for which sector in Switzerland are operational/real-time modelling, early warning, and seasonal forecasting of droughts and low flow most promising?

Project structure:

The project is divided into seven work packages (WPs). Two WPs frame and guide the project, by addressing the stakeholder survey-based establishment of relevant drought indicators (WP1) and an analysis of economic benefits of drought early warning (WP6). The natural system core of the project includes four WPs: Drought threshold analyses of past measurements (WP2) together with a novel characterisation of dynamic and total basin storage (WP3) will allow a quantification of the natural system’s vulnerability. Furthermore, drought simulation and forecasting by means of land surface and climate models (WP4) as well as distributed hydrological models (WP5) for the whole of Switzerland will be developed and tested. The results of WP1-6 will be integrated for the development of the prototype drought information platform (WP7), which will be available for testing by the end users by the end of the project.

Work packages:

• WP1: Critical drought and low-flow indicators for different water users (Lead: I. Seidl, M. Stähli; Contributions: All project participants)
• WP2: Analysis of critical drought thresholds and their connection with hydroclimatological variables from long-term observations (Lead: S.I. Seneviratne, J. Seibert)
• WP3: Analysis of critical low-flow conditions and storage characteristics of Swiss catchments (Lead: J. Seibert, M. Weiler, K. Stahl; Contribution: M. Zappa)
• WP4: Land surface modelling, early warning, and seasonal forecasting of soil moisture and drought (Lead: S.I. Seneviratne; Contribution: J. Seibert, M. Zappa)
• WP5: Operational hydrological modelling and snow water equivalent estimations (Lead: M. Zappa; Contributions: J. Seibert, S.I. Seneviratne)
• WP6: Economic benefit of an early warning system of drought and low flow (Lead: I. Seidl)
• WP7: Development of information platform for early recognition of critical drought (Lead: M. Stähli; Contributions: All project participants)

Contacts

• ETH Zurich: Prof. Sonia I. Seneviratne (PI), René Orth (Land-climate dynamics group)
• Uni. Zurich: Prof. Jan Seibert
• WSL: Dr. Manfred Stähli (Mountain Hydrology and Torrent), Dr. Irmi Seidl (Group Economics and Social Science), Dr. Massimiliano Zappa (Group Hydrological Extreme Events)
• Uni. Freiburg I. Brsg.: Prof. Markus Weiler and Dr. Kerstin Stahl (Institute for Hydrology)

Links

• NRP61 Program
• NRP61 DROUGHT-CH web page
• NRP61 video-clip on project