Urban transformation and heat island: Potential of urban design alternatives to mitigate the effects of urban overheating in Austrian cities

Abstract

Ongoing urbanization worldwide present a big challenge for the quality of urban life. This development poses great challengesfor cities due to the growing demand for more living space and supporting infrastructure, resulting in environmental pollution, higher anthropogenic waste heat and poor outdoor thermal comfort. To accommodate this rapid expansion of urban areas, the city authorities need to adopt a more climate-sensitive approach to urban transformation. In this regard, the present contribution investigates the potential of specific planning and adaptation strategies to attenuate the urban overheating for distinct urban locations in Vienna and Linz, Austria, over a hotsummer period. For this purpose, we applied the parametric modelling environment Rhinoceros 3D and a number of built-in algorithms in the Rhino’s plug-in Grasshopper for dynamic simulation of urban microclimate. The results were compared based on the meanradiant temperature (MRT) averaged over a 24-hour cycle and differentiated into day-and night-time shares. The results reveal a notable potential of selected greening measures to positively influence outdoor thermal conditions. The effectiveness of thesemeasures, however, seem to be time-dependent, whereby a more pronounced cooling effect was noted during the daytime, attributed to the solar shielding effect.