The city of Zurich is investigating ways to improve the quality of life with regard to the heat stress that the population has to endure within the framework of the specialist planning for heat reduction. To this end, the City of Zurich has presented a catalogue of measures that contains a variety of approaches to achieve this goal. Heat-reducing measures are highly dependent on local conditions and the effectiveness of the entire city climate system, so that there are no patent solutions.
For this reason, an individual examination of the effectiveness of measures is important and is also included in the implementation agenda in point M5.4 (Effectiveness of heat-reducing measures: Testing a modelling tool for planners and builders).
Simulations carried out so far have examined partial aspects of the underlying problem - on the one hand, simulations of atmospheric circulation in Zurich with FITNAH, on the other hand, microclimate simulations with ASMUS around individual buildings. The model PALM, which is now in focus, allows to combine these sub-areas and to perform urban climate simulations for entire city districts. PALM represents a new generation of urban climate models, which combines sophisticated flow simulations with microclimate-effective parameterizations. In particular, the different parameterisation of surfaces on the ground or facades and roofs on buildings allows the investigation of the effects of different parameters. The possible embedding of PALM simulations in large scale weather models makes it possible on the one hand to think of simulations for the entire city area, but on the other hand simulations that take into account different climate scenarios in the city of Zurich with time horizons of 2050 and 2100 could also provide insights into the longer-term effectiveness of measures.
Within the framework of the pilot project Zurich West initiated by the City of Zurich, the immediate effects of various measures in this region are to be investigated. The measures to be tested include, for example, a greening of facades or roofs, different albedo values of surfaces, increased water areas or additional shading possibilities.
The effectiveness of the measures can thus be determined on the basis of differences in temperature at pedestrian level.