Impact of Urban Morphology on Urban Heat Island Intensity in a Mediterranean City: Global Sensitivity and Uncertainty Analysis

Urban microclimate tools are used to estimate the magnitude of Urban Heat Island (UHI) and the effectiveness of mitigation strategies. However, acquiring information for creating reliable models is often challenging. Sensitivity Analysis (SA) and Uncertainty Analysis (UA) can be effectively used to acquire information and make informed decisions even in uncertain scenarios. However, few studies still carry out SA and UA on microclimate models. This study used SA and UA techniques to evaluate the impact of urban morphology on the UHI phenomenon in the Mediterranean climate during a summer heatwave period in Rome, Italy. The Urban Weather Generator (UWG) tool is used, coupled to SA and UA tools. The input parameters of four common Local Climate Zones (LCZs) are used to develop the urban model. The UA results show that the highest Urban Heat Island Intensity (UHII) occurs in LCZ2, the densest district among the selected LCZs. The SA confirms that LCZ parameters such as the mean height of buildings, building surface fraction and aspect ratio are the most influential ones in this study.