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AGWAM: Increasing water scarcity, also for Swiss agriculture

 

Rising temperatures and less summer rain will mean that agriculture is increasingly dependent on irrigation at a time when water is becoming scarcer. Based on different scenarios for climate, pricing and politics, researchers used models to investigate the options available to farmers.

Project description (completed research project)

The climate models project rising temperatures for the coming decades, and falling precipitation levels in summer, which would lead to a higher demand for water in agriculture while water availability in general drops. In order to irrigate high-value crops sufficiently and thus safeguard yields, more water will be needed in future. In areas with low run-off, water availability will be increasingly restricted. In these situations, we need strategies to reduce reliance on production of additional water. The aim of the project was to work out recommendations for dealing with water under different scenarios for climate, price and policy, and to find suitable strategies under which it would be possible to retain profitability without compromising environmental standards.

Methods

The case studies were carried out in the Broye-Tal and in the catchment area of the Greifensee. Two levels of decision-making were taken into account in the development of the strategies: the regional level and the operational level. The researchers used a model to simulate productivity and other agricultural goals on both decision-making levels. The results of this simulation provided the basis on which the team of researchers was able to generate solutions for regional optimisation. Three alternative strategies were developed based on these solutions that focused on either production, the environment or a compromise. On the operational level, an economic model was also used to find solutions offering the maximum profit levels and minimum income risks.

A life-cycle analysis integrated further categories into the evaluation of the solutions: potential for warming, aquatic and terrestrial biodiversity and nutrient inputs in the bodies of water. Stakeholders from the administration, interest groups and agriculture were included in the research process through the discussion of the action plan and the results.

Results

  1. In areas of Western Switzerland subject to periods of dry weather, the key issue is the increasing demand for water in agriculture in line with climate change. Balanced compromises will have to be made at regional level so that productivity can be maintained with as few conflicts as possible.
  2. Conflicts can be avoided and water use reduced with efficient irrigation technologies and adapted cultivation methods and crop rotation, the introduction of water quotas and changes to spatial planning.
  3. Restriction of irrigation paired with increased abstraction from reservoirs, while abstraction from sensitive sources should be avoided or subjected to strict quotas.
  4. Price and policy scenarios are more decisive for operational profitability than climate change. Adjustments can be controlled without significant loss of profit across the direct payment system, quota restrictions or the water price.
  5. A rise in production efficiency will still have a high priority, although it should be combined with restrictions in order to guarantee the protection of water resources.
  6. In the Greifensee region, a change in the choice of crops and land use is the more effective adjustment strategy, rather than changing irrigation methods.

Original title

Water demand in Swiss agriculture, and sustainable adaptive options for land and water management to mitigate impacts of climate change (AGWAM)

Project leaders​

  • Prof. Dr. Jürg Fuhrer, Forschungsanstalt Agroscope
  • Dr. Pierluigi Calanca, Lufthygiene/Klima, Agroscope Reckenholz-Tänikon (ART)
  • Dr. Gérard Gaillard, Ökobilanzen, Agroscope Reckenholz-Tänikon (ART)
  • Prof. Dr. Stefanie Hellweg, Institut für Umweltingenieurwissenschaften, ETH Zürich
  • Dr. Annelie Holzkaemper, Lufthygiene/Klima, Agroscope Reckenholz-Tänikon (ART)
  • Prof. Dr. Bernard Lehmann, Institut für Umweltentscheidungen, ETH Zürich