Microclimate analysis through advanced modelling: a case study in Lecce, Italy

The present study aims to analyse the effects of climate change on the urban environment, focusing on sustainable urban planning and an analysis of microclimate and thermal comfort. The considered study area is composed of a square domain of app. 400 x 400 m in the city of Lecce (Italy), where temperature and relative humidity data are still being measured.

The analysis involves a modelling chain that uses ERA5 data to provide the boundary conditions for the 1D Multi-Layer Urban Canopy Model (MLUCM) based on the BEP+BEM (Building Effect Parameterization + Building Energy Model) model, which subsequently generates the inputs for ENVI-met, a CFD model used for microclimate simulations and thermal comfort studies. This methodology allows us to bridge the gap between different scales.

Another model applied in this work is PALM-4U, which is an advanced atmospheric simulator for the simulation of urban atmospheric boundary layers, as well as urban climate and the interactions between the built environment and the atmosphere. It can work in turbulence-resolving LES (Large Eddy Simulation) mode, and is suitable for a wide range of applications, such as urban climate, air quality and pollutant dispersion, urban ventilation, and thermal comfort. Among the advantages of PALM-4U are its high spatial and temporal resolution, its modular approach, and the fact that it represents support for real data, as well as being open-source.

The modelling outputs are first validated against measured data and are further employed to develop strategies for adapting to climate change by improving urban thermal comfort for citizens.