The tropical storm threat to urban areas

Brian E. Lee
University of Portsmouth, Portsmouth PO1 3QL, United Kingdom.
Tel. : +44-1705-842423, Fax: +44-1705-842521,
E-mail: blee@civl.port.ac.uk

The tropical storm threat to urban areas has changed significantly in the past two decades. Cities at risk, particularly these on the shoreline of the N.W. Pacific typhoon zone now contain many more high rise fully glazed curtain wall buildings than in the past and for many reasons of architectural style and national prestige, this trend is likely to continue. The facades of such buildings are now at significantly greater risk from windborne debris than their predecessors and facade loss at a time of high wind speeds and driving rain brings with it loss of the building’s business contents, electronic machinery, records and commercial infrastructure. The cost of damaged glazing becomes trivial compared with the lost business opportunity costs.

An early warning system is being developed which combines an updated tropical storm wind field model, operable at a building size scale, together with a mathematical model which describes the flight of debris particles, and assesses their damage potential. The model is extended to cover the characteristics of debris likely to be found in an urban area and when integrated over the passage of a tropical storm, can yield a cumulative damage parameter. This information, when supplied to city authorities and building operators, will underpin economic assessments of debris control and building protection.