Estimation of probable maximum water level in Shanghai

The characterization of track and intensity change of tropical cyclone is analyzed that induces remarkable storm surge.It is shown that there are three kinds of track that affect Shanghai,they are westward moving of landfalling at the east coast of Zhejiang Province,northward moving inshore and positively hit Shanghai on the sea.The change in the tropical cyclone intensity as it passes the area near to Shanghai is remarkable.In general,the minimum surface level pressure of tropical cyclene center near to Shanghai is greater than 920 hPa.The probable maximum water level in Shanghai area estimated using the statistical method is about 210 cm.This is not suitable for the estimation of water level in Shanghai due to the lack of statistical method for the description of small probability.The results of numerical simulation indicate that considering the combination of probable tracks,estimated intensities and various velocities of tropical cyclone movement,the probable maximum water levels are calculated using a three-dimensional numerical model.The result indicates that the probable maximum water level appears when the track of TC 5612 is set to move 2°in latitude and the minimum sea surface pressure takes the lowest value in Shanghai.The estimated probable water level is 787cm.