The Mean Sea Level Changes in China Sea Area

The annual sea level of each long-term tidal station along the Chinese coast is analysed.The result shows that it has the feature of synchronistic rising and lowering.Its changing periods of 5,11 and 19 years are obtained by using the method of variance analysis. The comparison method of 11 years is used because the long-term tidal stations along the coast lack the observed tidal data with the record length of more than 38 years.The rising speed of 1.6±0.3 mm per year for the mean sea level along the coast in recent years(over 30 years) is obtained based on the data analysis of 13 selected benchmark tidal stations with a selected time interval close to the difference average of mean sea level of 11 years. This result agrees well with that of most researchers at home and abroad,and the method of analysis is easy to use.