Vulnerability and Adaptation of Hong Kong to Hazards under Climatic Change Conditions

Abstract

Given the evidence from past experience, the coastal city of Hong Kong would be vulnerable to a variety of hazards that could be exacerbated by climatic change, including potential increases in typhoons, landslides, floods (both storm surges and rainstorms), and droughts, as well as the threat of future sea level rise. The greatest death tolls in the past have been inflicted during typhoon-induced storm surges. During two unnamed typhoons, in 1906 and 1937, the deathtolls were 10,000 and 11,000, respectively. In contrast, death tolls associated with landslides and other hazards were relatively small. Under a climatic change scenario of an increase in frequency and severity of typhoons and rainstorms, and rising sea level, the vulnerable areas of Hong Kong can be identified. The shift in development from hillslope areas to coastal land reclamations over the last 25 years is a matter of concern. Although the hillslopes are susceptible to landslides during rainstorms, virtually all landslides can be traced to some important anthropogenic causes and are preventable with appropriate measures. In the coming decades, the low-lying areas created through coastal land reclamations could be susceptible to flooding during storm surges and rainstorms and as the sea level rises. These areas are also where there is high density urban and industrial development, and the vulnerability is the greatest. High seawalls to protect the reclaimed areas from storm surge flooding and sea level rise may increase the risk of rainstorm flooding. To reduce vulnerability, a combination of better monitoring, planning, protection, maintenance, and waming is proposed for adaptation. Monitoring is needed not only to detect future sea level changes but also to identify areas with the greatest risk.