Measuring mixed-use intensity in volumetric cities : density and interaction

Abstract

One of the most common measures used to describe the morphology of cities around the world is built density. However, density is an insufficient measure for capturing the complexity of interaction in cities in the 21st century. Instead, this paper argues that the structure of complex cities is better understood through spatial interaction measures of urban intensity. To that end, the paper proposes a new approach that works from the foundational elements of cities (land uses, density, networks, and flows) and utilizes network interaction methods from quantitative geography to capture urban intensity. The focus here is on the development of an accessibility-based approach to capturing built form, its spatial configuration, and potential to facilitate spatial interaction between different mixes of urban functions. This framework is applied to a case study of Hong Kong, a city which features a highly compact urban form, a layered multi-modal transportation network, and topographically-rich terrain. Results reveal how different configurations of the built environment are distributed over space and highlight the spatial pattern of interaction intensity across the central area of the city.