Strategies against urban heat islands: The importance of green spaces and water
In view of increasing global warming, which is creating more heat islands in cities, Swiss cities are focussing on innovative measures to reduce temperatures. These are aimed at increasing the proportion of vegetation and reducing surface sealing.
The challenge facing urban and industrial centres in the face of global warming is the phenomenon of heat islands, which is exacerbated by a combination of climate change and urbanisation. The overheating of urban areas results from a lack of vegetation and an excess of heat-absorbing surfaces such as concrete and asphalt. The high density of buildings and the lack of air circulation on narrow streets further exacerbate the problem.
To combat the negative effects of these heat islands, such as increased energy costs for air conditioning, air pollution and health risks, cities such as Zug and Zurich have begun to integrate comprehensive climate analyses and models into urban planning. The aim is to design new neighbourhoods in such a way that they contribute to reducing heat and do not lead to the creation of heat islands.
However, the adaptation of existing structures requires additional efforts. Many cities are exploring a combination of greening, the creation of water features and the use of building materials that absorb less heat. One example of this is the city of Sion, which has built a Japanese garden on the roof of an agricultural school and created a pond in front of the school building. In addition, soil sealing is being broken up and replaced with lighter-coloured asphalt to reduce heat storage.
It is clear that individual measures are not enough to solve the complex problem of heat islands. A holistic approach based on the motto “More green and blue instead of grey” is required to maintain and improve the quality of life in urban areas, even in hot summer conditions.