Definition of a new morphological parameter to improve prediction of urban heat island

Abstract

The impact of the urban heat island (UHI) on health of urban residents, energy consumption, and urban air quality has become increasingly significant in cities. Despite of multiple recent studies on developing UHI predictive models, the impact of vertical morphological parameters on the UHI formation is barely investigated. The current work investigates the extent of vertical morphological components impact on the UHI intensity and proposes a novel vertical urban morphological parameter defined as the elevation factor. Using remote-sensing satellite images and a GIS based approach, both horizontal and vertical morphological components of San-Francisco, as the case study city, was investigated for 20 representative built up areas. High-resolution geometrical data of these areas were then correlated with their land surface temperatures (LST). Linear regression analysis and ANOVA test revealed that the model with the newly proposed elevation factor has a significant impact on representing of the UHI behaviour with a coefficient of determination factor (R²) of 0.68. The model was then successfully validated with the UHI prediction of 24 randomly selected points from each of the five new areas. Furthermore, the impact of elevation morphology on the UHI intensity was investigated as the elevation factor was seen to provide a stronger correlation between urban morphology and UHI spatial distribution.