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  2. Thematische Synthese "Grundlagen" (German)

Forum für Wissen 2012 „Alpine snow and water resources – history and outlook“

Alpine snow and water resources

Although Switzerland is regarded as the reservoir of Europe, it cannot be relied upon to deliver the right amount of water in the right place at the right time. Under the influence of climate change, such variances will become even more pronounced in future. Various research groups at the WSL and SLF are investigating hydrological and climatological issues, and in particular the relationships that exist between snow, runoff, climate and natural hazards.

Messstation am Göscheneralp-Stausee
Measuring station at the Göscheneralp reservoir.

Exact measurement and monitoring for reliable forecasts

The WSL and SLF maintain a variety of snow and water measuring networks throughout Switzerland in order to record as accurately as possible when and how much snow and water exist. The employees in the SLF's operational snow-hydrological service (OSHD) continuously evaluate the current data and deliver hydrological bulletins to the flood forecasters of the National Environmental Agency (BAFU). They also use snowpack modelling to calculate the distribution of the snow in the field. Only on the basis of extensive current measurements and calculations can a reliable indication be given of future changes in the available snow and water resources. In order to investigate these future scenarios, the researchers bring together hydrological and meteorological computer models.

Schnee- und Wettermessstation

Snow and weather measuring station. Photographer: Ralph Feiner  

In national and international projects, the scholars work closely together with federal agencies, practitioners and other research institutes. By way of their scientific analyses, measuring systems and models, they support the efforts of the authorities, engineering offices, local agencies responsible for natural hazards and power station operators to develop strategies for managing the current and changing snow and water resources.

"Forum für Wissen" conference: sharing research findings and practical knowledge

The November 2012 "Forum für Wissen", the latest in a series of annual conferences hosted by the WSL, was entitled "Alpine snow and water resources – history and outlook". Experts from the field joined scholars, business representatives, public administrators and associations to present and share their current knowledge of the subject matter.

Challenges presented by climate change – one of many items on the conference agenda

In his presentation, Hugo Aschwanden of the BAFU's water resources management section began by confirming that Switzerland would continue to have sufficient water at its disposal in the future. In view of the trend towards drier summers and wetter winters, as well as the sharp decline in the quantities of water stored in snow and ice, however, he pointed out that the seasonal and local distribution of the water resources will change in future. This will exert a substantial influence on the runoff quantities entering mountain streams and rivers.

Bach im Vorfeld des Dammagletschers.

Stream in the forefield of the Damma Glacier.

Massimiliano Zappa, head of the WSL's hydrological forecasting research unit, outlined the scenarios that are to be expected in the future. The peak runoff rates in the spring, for example, fuelled by melting snow in particular, will occur earlier. This change is especially significant for hydropower generation. As a general rule, more runoff is likely to take place during the winter, and flooding could occur as a consequence. Southern Switzerland, in particular Ticino, is likely to be affected by water shortages.

Such changes in the snow and water resources can give rise to supply bottlenecks and aggravate conflicts of interest concerning utilisation. According to Aschwanden, the principal challenges from a water management perspective arise from summer drought, the rising snowfall level, the increasing flood risk, and the impairment of water, soil and air quality. Apart from taking other measures, the Swiss government has responded with a strategy for adapting to climate change (only in German). The main areas for action highlighted by the strategy are the drinking water supply, integrated reservoir management, a review of the residual water regulations, and flood protection (cf. conference proceedings, pp. 43-50).

In its response to the postulate of the MP Hansjörg Walter (only in German), the lower house of parliament recently adopted further measures to manage the country's water resources in the light of climate change including, for example, the establishment of an early warning system for drought.