Typhoon wind hazard estimation for China using an empirical track model

A probabilistic model for simulating tropical cyclone (TC) track from the genesis to lysis is developed based on historical best-track dataset for western North Pacific basin. The spatially varying model coefficients are determined through regression analysis. Tracks are simulated using the developed probabilistic model; statistics of the key parameters defining the TC track: the translation velocity, storm heading and, relative intensity that is a function of central pressure difference, are estimated at sites along the coastline using the simulated tracks. The statistics of the key parameters are compared with those estimated using historical tracks, indicating the adequacy of the developed empirical track model. The developed track model together with a well-established planetary boundary layer wind field model are subsequently used to assess the TC or typhoon wind hazard, in terms of the return period value of the annual maximum TC wind speed, for coastal region of the mainland China. The estimated wind hazard at selected sites is compared to that based on the circular sub-regional method. Comparison is also extended to the values recommended in Chinese design code at many sites, and the results from the surface wind observations at four sites. It is shown that the estimated typhoon wind hazard is consistent with that derived based on surface wind observations, and the mapped typhoon wind hazard near the coastal line is in good agreement with that presented in current design code.