Tropical Cyclone Wind Hazard Assessment for Southeast Part of Coastal Region of China

Tropical cyclone (TC) or typhoon wind hazard and risk are significant for China. The return period value of the maximum typhoon wind speed is used to characterize the typhoon wind hazard and assign wind load in building design code. Since the historical surface observations of typhoon wind speed are often scarce and of short period, the typhoon wind hazard assessment is often carried out using the wind field model and TC track model. For a few major cities in the coastal region of mainland China, simple or approximated wind field models and a circular subregion method (CSM) have been used to assess the typhoon wind hazard in different studies. However, there are differences among the values given by these studies and by the Chinese building design code. Moreover, there is a lack of a TC full track model simulating the TC from genesis to lysis developed for China. A TC full track model and a planetary wind field model (PBL) have been applied to assess the hurricane wind hazard for the U.S. and used to update the U.S. design code. This study finds this PBL wind field model is approximated and the effect of such approximation on the estimated hurricane wind hazards needs to be investigated. By using the best track dataset given by HURDAT, the TC full track model and a simplified version are developed for the U.S. The performance of the simplified TC full track model is verified and found to be comparable with the full version. For assessing the typhoon wind hazard for China, the best track dataset released from China Meteorological Administration (CMA) is used. The PBL wind field model is used with the CSM to assess a few coastal cities of mainland China. The practice is extended to cover the whole region of the southeast part of mainland China to develop the contour maps of the typhoon wind hazards. By using the CMA best track dataset, a full track model is developed for the western North Pacific basin. This full track model is combined again with the PBL wind field model to assess the typhoon wind hazard for mainland China. The results obtained by using the full track model are compared to those estimated by using CSM, by using long term ground observations and tabulated in the Chinese building code