Three Dimensional Spatial Metrics for Compactness Assessment of Urban Forms

Abstract

-Developing measurement tools to assess urban sustainability is one of the new streams in built environment; however, automated methods of urban form assessment are technically difficult. While planar characteristics of urban forms have been studied traditionally using the spatial metrics from remote sensing data such as Landsat images, height information of urban environments is now playing an important role in urban energy exchange (e.g. solar energy gains), urban air circulation (which is affected by interactions between terrain and buildings) and urban microclimate. As incorporating the planar metrics and the height information has been rarely attempted in the sustainable urban form studies, we propose an automatic technique for the quantification of 3-dimensional urban compactness which is one of the main factors influencing sustainability. In this paper, we aim to utilise one of autocorrelation statistics known as Moran's for the assessment of urban form compactness, considering both layout and elevation attributes. Additionally, Getis-Ord statistic is also used for further investigation on concentration of low or high urban features.