Discussion on the Defence Criterion of Disaster Prevention Engineering in Coastal Region

In recent years, the frequency and intensity of the typhoon is gradually increasing on account of the global warming and sea level rise. The disasters induced by typhoon are complex, such as strong wind, huge waves, storm surge, heavy rain, floods, and so on. In consideration of the lessons from disasters and complexity of typhoon, a statistical and numerical model based the on Double-Layer Nested Multi-objective Probability Model (DLNMPM) and numerical model was established to calculate the probable maximum storm surge with different combinations of typhoon characteristics. In this model, the long term probability characteristics of typhoon factors such as the typhoon occurring frequency (λ), drop of central pressure (ΔP), radius of maximum wind speed (R_max), typhoon moving speed (S), minimum distance between typhoon center and certain area (δ) are considered, and the storm surge of Hangzhou Bay in Zhejiang Province is carried out as example. The results predicted by this model can offer a useful reference for the defence criterion of the coastal regions for its probabilistic meaning.