Decoding multi-layered urban form : morphology, pedestrian network and human behavior in the volumetric urban tissue of high-density Hong Kong

Abstract

Wan Chai, a central district in Hong Kong, characterized by dense, high-rise structures, contrasts low-density towns usually studied in urban analyses. This research explores volumetric urban form evolution and its impact on pedestrian movements in Wan Chai. It extends beyond standard two-dimensional analysis to a three-dimensional approach, assessing the hierarchical structure and morphological composition of buildings, plots, and streets. By integrating these findings with traditional network models and vertical urban network, the study offers a comprehensive understanding of pedestrian dynamics in high-density areas, enhancing traditional methodologies with the interplay of urban form and pedestrian movement.

The dissertation unfolds development of Wan Chai in four stages, from a mid-19th-century irregular cluster on sloping terrain to early and mid-20th-century colonial, compact street gridirons, and eventually to a late 20th-century high-rise, high-density and interconnected development on reclaimed land. Each stage exhibits unique urban patterns, facilitating comparative analysis. The research delineates evolved urban component elements, clarifies complex spatial relations, and quantifies the intricate organization of urban patterns into clearer hierarchical spatial structures of streets, plot open areas, and building floors for each stage. It highlights the contrast between the orderly, compact, and efficient colonial street gridirons and the more complex, loosely organized, and less structured contemporary urban hubs.

Interdisciplinary graph-based models are developed to analyze the relationship between evolving layouts and pedestrian accessibility of Wan Chai. A new network model is proposed for identifying optimal radii for different neighborhood patterns, moving beyond experiential radii. Additionally, modified gravity models are introduced to merge quantified spatial structures with urban network properties. Based on the three-dimensional graph, the model examines the impact of four stages’ morphological composition on pedestrian movement. The results indicate that specific hierarchical spatial factors significantly influence pedestrian movements. The final part of the study compares on-site observations with the outcomes of the developed models, affirming the effectiveness of these methods. This analysis underscores the significance of comprehending morphological changes and their interaction with human behavior patterns in the high-density cities. The understanding is crucial both for advancing urban morphology theory and for informing urban planning and land development decisions in similar high-density urban settings globally.