Influence of the urban morphology on the urban heat island intensity: an approach based on the Local Climate Zone classification

Abstract

This article presents the development and application to a set of French urban agglomerations of a method for Local Climate Zones (LCZ) attribution using the open-source language R. The LCZs classify the urban fabric at high spatial scale (such as a block of houses) according to its morphological characteristicsand land use. The LCZ classification is carried out for 42 urban agglomerations and is then related to urban heat island intensity (UHII) obtained from numerical simulations at a spatial resolution of 250m. The objective is to study the adequacy of the LCZ classification to characterise the impact of urban morphology on the UHII. The variance analysis (ANOVA) carried out confirms the highly significant relationship between LCZs and the UHII for a given urban agglomeration. For all the urban agglomerations in the sample, linear regression models show a significant correlation between the percentages of surface covered by different LCZ and the mean UHII for the time periods tested (21-23 UTC), with adjusted coefficients of determination higher than 0.40.