Which regions of Switzerland are most affected by drought?
A drought is a period of significantly below-average precipitation that leads to water deficits in the soil, in watercourses and in the groundwater, and thus affects natural and human systems.
The map shows the combined drought index for each region. This index summarises in one value the various factors affecting drought: precipitation, modelled soil moisture and discharge (watercourses) or water level (lakes). The index is calculated by determining the extent to which the variables deviate from the statistically expected values for the measurement period 1991–2020 (known as the ‘reference or standard period'). It primarily shows how often an event occurs and can assign a value from 1 to 5. The higher the value the more unusual or extreme is the water deficit for the season.
Link to the map: map.geo.admin.ch