Abstract: The study was based on the improved 3-D estuarine, coastal and oceanic model ECOM-si, in which a model of sea surface pressure and wind fields was embedded. By coupling the action of runoff, astronomic tide and storm surge, water level process in the Changjiang estuary and the Hangzhou Bay during three typhoons(No. 9711(Winnie), No. 0012(Prapiroon) and No. 0014(Saomai)) were simulated in this paper. The model revealed well the water level process during three typhoons. The simulated storm surges by Fujita pressure formula(formulaⅡ) were better fitting the observed than those by FujitaTakahashi pressure formula(formulaⅠ). The mean square errors between the simulated and the observed water level by formulaⅡduring three typhoons were 42.5 cm, 41.7 cm and 35.5 cm, respectively.

Key words: 3-D numerical simulation, pressure field, wind field, storm surge, storm surge, 3-D numerical simulation, pressure field, wind field, storm surge