Spatial inhomogeneity analyses of extreme sea levels along Lianyungang coast based on numerical simulation and Monte Carlo model

The prediction of extreme sea levels in coastal areas has been a prominent requirement of coastal engineering design and planning. The research was based on the frequent disasters caused by typhoon storm surges in China and the demand for reasonable improvement of port structures in coastal areas. Delft3D hydrodynamic model and the Monte Carlo model were integrated to predict the spatial distribution of extreme sea levels along the coast of Lianyungang city in Jiangsu province. The Monte Carlo model was adopted to generate stochastic typhoon characteristic sequences as meteorological driving forces. In the hydrodynamic model, meteorological factors were coupled with the astronomical tide to simulate storm surge scenarios. Extreme sea levels were estimated by ranking maximum levels of simulated storm surge events. This programming was feasible compared to the prediction results of frequency analysis methods. The research showed that the predicted 1 in 100-year extreme sea level of Lianyungang station was 3.75 m, while the predicted 1 in 200-year value was 3.85 m. The programming was adopted to predict extreme sea levels of several stations and analyze the spatial distribution characteristics of extreme sea levels in four port areas of Lianyungang Port. Results revealed that extreme sea levels in modeling areas had significant spatial inhomogeneity, which might be related to the concavity of coastlines, islands, and terrains. Estimating spatial extreme sea levels could better cognize the influence of inundation disasters in coastal areas and be conducive to the design of port structures and the safety of port operations.