The calculation of maximum elevation due to storm surge by using joint probability method

Abstract

In the present paper the maximum storm surge elevations with certain return years were calculated by using a joint probability method. Based on the analyses of the typhoons which, affected coastal zone of Guangdong Province in history, a group of model typhoons was established. A number of parameters, which described the typhoons, were selected. The data of each parameter I was graded into a few sub-groups according to their values, and this was done in accordance with the historical observations. The probability of each value of the parameters was calculated based on the historical records. The probability of a typhoon with a group of values of parameters could be calculated. Simulation results of the storm surges caused by the above model typhoons with their probabilities were analysed statistically. Thus an accumulated probability curve and maximum elevations with certain return years were obtained.

A number of spots was selected. At some of the spots there are tidal stations and at the others there are none. The maximum elevations with certain return years at the spots were calculated and the results were found satisfactory. By using this method all the meteorological and hydrological data, which were available, can be fully utilized. This method is most suitable for calculating the  maximum elevations at a place where there is no tidal station or at many places simultaneously.