Multi-hazard risk assessment of two Hong Kong districts

Abstract

The assessment of multi-hazard risks in urban areas poses particular difficulties due to the different temporal and spatial scales of hazardous events, and the potential interactions between hazards and socio-economic fragilities. Yet this exercise is important, as identifying the spatial distribution and concentration of risks in urban areas helps determine where and how preventive and corrective actions can reduce levels of vulnerability and exposure of urban populations. This article presents the results of a GIS-based assessment of present day risk to socio-natural hazards in two socio-economically distinct districts of Hong Kong (PRC) by utilizing indicators to describe the hazards and vulnerabilities. Hong Kong is a densely populated coastal metropolis exposed to multiple intense and potentially overlapping hydro-meteorological hazards, including heat waves, typhoons, and landslides. Mapping hazards and vulnerabilities in this urban area helps to visualize the spatial distribution and concentrations of risk located throughout the city, and thereby facilitate the tailoring of measures that can reduce risk at the very local scale. This approach has the potential of providing city planners and policy makers with visual guidance in prioritizing risk management and adaptation actions with respect to current and future risks existing in specific parts of the city, taking into account more than one hazard at the time. We found that the two districts considered have comparable and distributed levels of risk being both exposed to multiple hazards and notwithstanding the socio-economic groups. However, elements of criticality are potentially more widespread in the less wealthy parts of the city.