A Numerical Study On Hurricane Induced Storm Surge And Inundation In The Near Shore Of TianJin

China is one of the pacific-coastal countries which are frequently suffered from the storm surge disasters. It is essential to improve the prediction accuracy of storm surge models to mitigate disaster impacts on cost over economy and personnel. In terms of the present investigation on this topic, three-dimensional storm surge inundation model with dynamic boundary condition is built upon POM. Several typical cases are simulated within the coastal area of Tianjin during the hurricane season.Double-layer-grid nesting is applied in the model: the oceanic region simulation with fixed boundary is performed within the whole Bohai Sea in the first layer;the coastal region simulation with dynamic boundary is calculated within the Tianjin near-shore in the second layer. The resolution is enhanced through the method of proper nesting between two layers, sufficient covering of wind field in the first layer, and high-resolution simulating of the shallow water region in the second layer.The dry-wet grid method is introduced in the second layer. It is realized by adding judgment condition and keeping the rest boundary conditions same as the POM. The motion of the water level under the hurricane is simulated in a high resolution. The Flather-Heaps dry-wet grid method is also easy handling without increase of programming complexity and running time.Time-series of water level change are computed for hurricane 7203, 8509, 9216 and 9711. Simulation results agree well with the field datameasured at Tanggu station, and it properly reflects the water level change and inundation area under storm surge. Given the reasonable work of this paper, it is highly feasible to revise the classic POM to numerical model with dynamic boundary for the shallow water area research.