Dynamic Process Simulation And Risk Assessment Of Storm Surge Disaster In Liaodong Bay

Liaodong Bay,one of the three major bays in the Bohai Sea in China,is located at 39 degrees north latitude.It is the bay with the highest latitude in China.Since its own records,storm surge disaster is one of the main marine disaster factors causing economic losses in Liaodong Bay.At present,the domestic research on storm surge disaster mainly focuses on the southeast coastal area.After decades of large-scale development and utilization,the characteristics of coastal space in Liaodong Bay have changed greatly.At the same time,with the change of global climate,the risk of storm surge in Liaodong Bay is increasing year by year,and the economic loss caused by storm surge in Liaodong Bay is also on the rise.This paper simulates the dynamic process of storm surge disaster in Liaodong Bay,and analyzes the impact of storm surge disaster on wetland vegetation and port terminals in Liaodong Bay according to the simulation results.The main research work and results are as follows:(1)Based on the GPUOM hydrodynamic numerical model of GPU parallel algorithm,a storm surge model is established.By adding the modules of uneven wind field,pressure field and precipitation field,the model can simulate the storm surge process according to the existing meteorological data.Through the comparative study of three different calculation formulas of wind drag force coefficient,the storm surge process caused by a cyclone which is from land to sea is simulated respectively.According to the simulation results,the calculation module of free surface wind stress of the improved model is compared and improved.(2)Simulate the impact of the cyclone which is from land to sea from west to East on wetland vegetation in Liaodong Bay,and divide the dangerous area of vegetation affected by storm surge.The improved GPUOM model is used to simulate a cyclone process,analyze the risk of storm surge disaster caused by cyclone from land to sea as a disaster causing factor,and study the vulnerability of wetland vegetation in Liaodong Bay,mainly Suaeda salsa and reed.At the same time,by comparing the differences of wind field and pressure field between offshore cyclones and tropical cyclones moving in the Bohai Sea,combined with the storm surge simulation results,the differences in the impact of storm surge disasters are analyzed.(3)Simulate the impact of four tropical cyclones(typhoons)from south to North on Panjin Port in Liaodong Bay,and calculate the storm surge risk index in the process of each typhoon in the port.This paper collects and arranges the typhoon process data passing through the Bohai Sea from 1960 to 2021,divides it into four categories according to the typhoon trend and influence area,and selects one typical typhoon process respectively,then simulates the storm surge disaster dynamic process of the four typhoon processes,and verifies the model simulation results according to the measured data of Bayuquan station,huludaokou station and Tanggu station.Finally,the storm surge risk index of Panjin Port is calculated according to the simulated storm surge water increase and maximum water level.The risk level of storm surge during the four typhoons in Panjin Port is divided by the scale of port functional area.(4)Construct a risk assessment system for port storm surge disaster.Based on the three essential factors of typhoon as the disaster causing factor,personnel,operation equipment and goods in the port as the disaster bearing body and the geographical and hydrological environment of the port area as the disaster pregnant environment,the risk conceptual model is established,and the weight of the influencing factors is determined by the analytic hierarchy process to construct the port storm surge risk assessment system to evaluate the impact of the four typhoon processes on Panjin Port.The research of this paper enriches the functions of GPUOM model,and can provide a certain theoretical basis and reference for the follow-up study of the impact and risk assessment of storm surges caused by cyclones from land to sea or typhoons on Liaodong Bay wetlands and ports.