Counteracting urban climate change: adaptation measures and their effect on thermal comfort

TLDR

Cities are thermal load areas, and climate change will increase summer heat events. The study aims to evaluate mitigation and adaptation strategies to counter urban climate change. Meteorological measurements across local climate zones and ENVI‑met simulations in Oberhausen were used to quantify how evaporation surfaces and other factors influence physiologically equivalent temperature. Increasing wind speed reduced PET by up to 15 K, while vegetation combining shading and evapotranspiration yielded greater PET reductions than water surfaces, supporting the creation of park areas with water supply and tall shade trees for ventilation.

Abstract

Cities represent thermal load areas compared with their surrounding environments. Due to climate change, summer heat events will increase. Therefore, mitigation and adaptation are needed. In this study, meteorological measurements in various local climate zones were performed to demonstrate the influence of evaporation surfaces and other factors on thermal comfort, as determined by the physiologically equivalent temperature (PET). Furthermore, a quantification of the thermal effects of several adaptation measures and varying meteorological parameters was made using model simulations (ENVI-met) in an inner-city neighborhood (Oberhausen, Germany). The results show that the most effective adaptation measure was increased wind speed (maximal 15 K PET reduction). Moreover, vegetation areas show greater PET reductions by the combination of shading and evapotranspiration than water surfaces. The creation of park areas with sufficient water supply and tall, isolated, shade-providing trees that allow for adequate ventilation can be recommended for planning.