Modelling and observations of green and blue adaptation measures

Since more extreme heat events occur and will occur under climate change, it is important to adapt urban environments in such a way that the population is safeguarded from extreme heat stress as much as possible. It is however unclear how green, blue and brown infrastructures perform in real urban redevelopments. The redevelopment of the main square of the city of Genk (Belgium) was therefore studied with in situ observations and microclimate modelling. Three weather stations were placed onsite, each capturing a different micro-environment both before and after redevelopment and an additional station served as a reference by maintaining the same micro-environment before, during and after the redevelopment. During August 2023 and 2024 the stations measured 2 m-air temperature, black globe temperature, relative humidity, wind speed and direction, making it possible to derive outdoor thermal comfort indices. This data is used to validate the ENVI-met microclimate model, which in turn is employed to model the complete local environment. This allows us to identify the microclimate and thermal comfort impact of persisting, new and removed green, blue and brown infrastructures in their specific environments. The model approach allows us to evaluate the effects of these nature-based adaptation measures under different climate scenarios and regional development scenarios. Such knowledge can be directly translated into practical appliances, mainly allowing urban planners and architects to better design climate proof living environments. A similar observation and model strategy will be employed in six other Belgian cities to verify the outcomes.