Validation of an Offline One-Dimensional Multi-Layer Urban Canopy Model Using the BEP+BEM Scheme: A Case Study in Melbourne

Rapid urbanization and climate change have intensified the need for accurate urban microclimate modelling tools to support sustainable urban planning and mitigate adverse environmental impacts. Models capable of simulating the complex interactions between urban surfaces, buildings, and vegetation are essential for assessing the effects of climate change, urban overheating, and energy consumption. The MLUCM BEP+BEM model introduces advancements in urban microclimate modelling by integrating enhanced turbulent diffusion schemes with the Building Effect Parameterization (BEP) and the Building Energy Model (BEM). The model incorporates updated turbulent length scales and eddy diffusivity coefficients that account for atmospheric stability, as well as a representation of urban vegetation, including green spaces and street trees. Designed for offline operation, it offers low computational cost, making it suitable for standalone use, coupling with climate projections, and conducting long-term simulations to assess the effects of different emission scenarios on urban environments. Validation against observational data from the Urban-PLUMBER project, conducted at a suburban site in Preston (Melbourne, Australia), demonstrates reliable performance in simulating upward shortwave (SWup) and longwave (LWup) radiation. Sensible heat flux (Qh) and momentum flux (Qtau) are also accurately reproduced, highlighting the model’s robustness in complex urban environments. An underestimation of latent heat flux (Qle) suggests that further investigation and refinement of the representation of moisture-related processes in the model would be beneficial. The adaptability of the MLUCM BEP+BEM model enables its application across various climatic contexts to evaluate the impacts of climate change on urban heat stress, energy demand, and the effectiveness of adaptation strategies. Potential applications include analysing green roofs, cool roofs, photovoltaic systems, and other mitigation measures to support sustainable urban development.

This work is supported by ICSC – Centro Nazionale di Ricerca in High Performance Computing, Big Data and Quantum Computing, funded by European Union – NextGenerationEU (CUP F83C22000740001).