Correlation between spatial characteristics and overflow rate of back alleys in high-density city of Hong Kong

Abstract

In recent years, scholarly attention has shifted within urban informality research from informal settlements to the appropriation of public spaces in formal urban settings. Overflow, a common research subject within this context, has drawn particular interest. This study investigates overflow dynamics in a representative district of Hong Kong, utilizing the overflow rate as a measure of the extent to which overflow occurs. Three-dimensional (3D) scanning technology was applied to collect spatial data from back alleys. Multiple linear regression analyses were conducted to identify the spatial characteristics of back alleys that influence overflow rates. The results revealed that back alleys with a flatter spatial interface, more overhead shelter, greater numbers of alley-shops, and shorter overall length corresponded to a higher number of overflow occurrences. Two novel findings emerged: First, a negative correlation between spatial interface unevenness and overflow rates, and second, differential impacts of the shop density and number of alley-shops on overflow rates. These findings may serve as a valuable reference for governmental policy formulation regarding overflow management and may offer architects workable insights for designing back alleys and street spaces conducive to public use.