Modelling of the annual mean maximum urban heat island using 2D and 3D surface parameters

The primary aim of this study was to reveal quantitatively what effect urban structure has on the development, magnitude and spatial distribution of the annual mean maximum urban heat island using a selected representative sample area in Szeged, Hungary. In order to quantify what effect urban structure has on the development of the mean urban heat island a relatively new surface parameter (weighted volumetric compactness) was used that characterises the volume, structure and thermodynamical role of buildings, This new parameter was used in conjucntion with other established surface parameters. How the new parameter and other surface parameters can pinpoint the magnitude and structure of the heat island was investigated. The compactness of approximately 11000 buildings in one-third of the town was determined by geoinformatical analysis. A stepwise multiple linear regression model was used to determine to what extent each parameter adds to the annual mean urban heat island intensity. According to the results presented here, the connection between compactness and the annual mean ('all weather') heat island intensity is stronger than with the sky view factor. Using this model-equation, the absolute deviations of the generated heat island (calculated for an independent 1 yr period) remained under 0.5 degrees C throughout almost the entire investigated area of Szeged. The structure of the estimated heat island with its characteristic features showed clear similarities to the real conditions.