Dryness: National Platform for Natural Hazards

Summers with little rain and winters with little snow are becoming increasingly frequent. Switzerland is considered Europe's water tower. However, as precipitation is expected to decrease during the summer months in the future, the effects of drought will be more noticeable.

Dryness

reduces agricultural yields,
threatens forests and their services, including the function of the protective forest,
increases the risk of forest fires,
jeopardises the ecosystem
jeopardises water resources and thus also energy production.
MeteoSchweiz, Drought

The damage can cause high costs. Drought affects everyone and can lead to conflicts of interest regarding water use: between the concerns of society, agriculture and environmental protection.

Effects of climate change

More rain-free days

As climate change progresses, the tendency towards drought continues to increase. Towards the end of the century, a drought that has previously occurred once or twice every ten years could occur every second year.

The National Centre for Climate Services (NCCS) predicts that on an average rainy day in summer there will be a similar amount of precipitation as before. However, the number of rain-free days will increase. According to the 2060 scenario, the longest dry period of the summer could last on average up to around a week longer than today.

As climate change progresses, the tendency towards drought continues to increase.

Not only does it rain less often - because of the higher temperatures, more moisture evaporates than today. The soil will become drier even in periods of constant rainfall.

Warning system structure

The drought affects everyone directly and/or indirectly

Development of a warning system

In 2022, the Federal Council decided to set up a national early detection and warning system by 2025. It should indicate several weeks in advance if a critical situation is imminent. This will give drinking water suppliers and farmers time to take appropriate measures.

Effective measures

Drought affects everyone directly and/or indirectly. In order to meet the drinking water requirements of the population as well as the needs of the agriculture (economy) and the environment, the communes and cantons must undertake overall planning. The federal government outlines various options for action to help agriculture cope with the drought. Examples of further measures include

Biological measures

Planting trees and hedges to provide shade
Create and maintain water features
Improve water retention in agricultural soils by building up humus
Cultivate drought-resistant plants such as trees, vegetables, cereals and shrubs
Create and maintain drought-resistant protection forests

Technical measures

Unsealing surfaces
Store water with reservoirs, reservoirs or rainwater collection basins
Conserve drinking water resources
Install an efficient irrigation system

Canton Solothurn leads the way

How can farmers keep their livestock in dry/warmer conditions? And how do they irrigate their crops? The canton of Solothurn has formulated specific measures for agriculture in an action plan for adapting to climate change, such as advice on livestock farming or the development of irrigation concepts.

Adaptation to climate change (action plan, 2016)

Chronicle

Many dry summers in the last 20 years

2003

There was also a pronounced drought during the hot summer. The water levels sank to the point of drying out. In the remaining water, the temperature rose to such an extent that fish and other creatures were severely threatened: Among other things, this led to the mass mortality of 50,000 grayling in the Rhine below Lake Constance.

Hot summer 2003: the effects on water bodies: melting glaciers and dried-up streams (admin.ch)

2018

With an average temperature of 15.3 degrees in June, July and August, 2018 was the third warmest summer since measurements began in 1864 after 2003 and 2015. The amount of precipitation was also very low. Water became scarce for the animals on many alpine pastures. The army transported water by helicopter and the civil defence set up emergency wells.

Summer 2018: Drought in Switzerland (admin.ch)

Summer 2022

The drought caused water to become scarce and springs to dry up during the record-breaking summer. Groundwater levels and watercourse levels fell to historically low levels. In some cantons, there were supply bottlenecks in the water supply. There were considerable crop losses in agriculture.

BAFU, Heat and drought in summer 2022

Winter 2022/23

The winter was very dry. The low water levels on the Rhine made shipping on one of the most important waterways more difficult, which made the transport of fuel more expensive.