Warning Water Level Determination for Luchaogang of Shanghai

Based on "specification for warning water level determination" (GB/T17838-2011), long-term tidal data at Luchaogang are used to determine warning water level along the Luchaogang Coast. The influence of Seawall defense standards, the social and economic situation behind the dikes, and historical storm surge disasters are also taken into account to calculate the warning water level. Four levels, Red, Orange, Yellow and Blue, of warning water level are obtained with the value of 5.40m, 5.13 m, 4.87 m and 4.60m, respectively. The results are verified against the observed daily high water levels in 1977-2010. It reveals that the extreme water levels occurs mostly during typhoon period.