Cyclone wind hazard assessments for eastern coastal cities in India using a fast-predictive model

Abstract

Tropical cyclone wind-induced hazards for the eastern coastal built environments of India can be severe. The extreme cyclone winds can cause damage to structures and infrastructures and losses of lives and economies. The current building code of India provides design wind speeds for the eastern coastal cyclone-prone regions. These design wind speeds were determined without considering extreme wind speeds associated with different weather types, such as thunderstorms or cyclones. The cyclone simulation technique has not been considered to update the design wind speeds for India's eastern coastal cyclone-prone regions. Several previous studies used the regional maximum sustained wind speeds to derive the design level cyclone-induced wind speeds. This approach differs from advanced cyclone simulation techniques and provides overly conservatism. The effect of using the regional maximum sustained wind speeds of cyclones in estimating the design wind speeds was investigated quantitatively in this study. A fast-predictive cyclone wind hazard model was proposed to assess the cyclone wind hazards. This model used simple wind field modeling and directly applied the historical best track datasets. The performance of this model was validated by comparing the predicted design level tropical cyclone wind speeds for selected coastal cities in the USA and China to those provided by the local building code or reported in previous studies using advanced tropical cyclone simulation models. This fast-predictive model was used to calculate the peak cyclone wind speeds and predict the 50-year return period cyclone wind speeds for twenty eastern coastal cities in India. The predicted 50-year return period cyclone wind speeds using the fast-predictive model were compared with those predicted using the regional maximum sustained wind speeds and current code design wind speeds.