Drought
As part of the «Drougth Project», the Federal Office of Topography swisstopo, the Federal Office of Meteorology and Climatology MeteoSwiss and the Federal Office for the Environment FOEN are jointly developing a national early warning system for drought. Swisstopo supports these efforts by providing pre-processed satellite images and vegetation indices that can be analysed.
What is it about?
The «Drought Project» has several objectives: a national system for the early detection and warning of drought has been developed and is operational since spring 2025. This will be expanded to include a comprehensive information platform providing information on the current drought situation and forecasts throughout Switzerland. The platform is based on the existing drought.ch research platform of the Swiss Federal Institute for Forest, Snow and Landscape Research WSL. Drought.ch will continue to be operated and expanded as an experimental platform.
The project was launched by the Federal Council in May 2022 in response to the increasing number of drought events in recent years, with the aim of creating the basis for a coordinated national warning system. The warnings are accessible via the new drought platform, the federal government's natural hazards portal, the MeteoSwiss website and the MeteoSwiss app
The information provided by swisstopo – e.g. products derived from satellite data – enables those affected to take measures at an early stage to avoid or minimise damage. Specifically, swisstopo provides comprehensive monitoring information in map form via the «swissEO VHI» product. The data is available for download and as an interface for third parties via open data.
Project content and responsibilities of the offices
The Drought Project is being implemented jointly by three federal offices: swisstopo, MeteoSwiss and the FOEN. Each office is making specific contributions to the development of an effective monitoring, early detection and warning system.
swisstopo provides geodata products. This includes
- processing high-resolution satellite images, in particular from Sentinel-2 in the «swissEO S2-SR» product,
- combining data from various satellites into a single product for vegetation monitoring in collaboration with MeteoSwiss,
- ensuring traceable geodata processing, provision, and publication,
- defining interfaces for a seamless collaboration with project partners and users.
MeteoSwiss is responsible for
- the development and operation of a national soil moisture measurement network,
- the creation of drought indices and warning indicators,
- meteorological forecasts of drought-relevant parameters over longer periods (4 weeks),
- satellite-based monitoring of plant stress with swisstopo.
The FOEN
- manages the project,
- coordinates the development of the information platform and the warning chain,
- coordinates cooperation with other federal offices and cantonal authorities,
- is responsible for monitoring and modelling hydrological, hydrogeological, and forestry impacts.
By using the latest technologies, swisstopo supports satellite-based monitoring of drought and thus makes a significant contribution to national drought monitoring.
Current situation
The map of vegetation condition based on the VHI (Vegetation Health Index), which shows the current condition of vegetation (or specifically of forests) in relation to the climate reference period 1991-2020.
VHI Warning regions: Current and historic monitoring values
VHI Detailed view: Current and historic monitoring values
Media collection
Media collection: Visualising drought
This media collection provides a comprehensive overview of how remote sensing can be used to detect drought and other stressful situations for vegetation. From high-resolution true-colour satellite images documenting visible changes in the landscape to specialised indices and thematic maps, you will find a wide range of image material to help you understand drought phenomena.
Links
FOEN drought: monitoring, forecasting and warning
Index
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