Simulation Of Typhoon Surge-wave And Risk Analysis Of Fishing Port

Typhoon storm surges and wave disasters attack Zhejiang province frequently and cause severe damages every year,espciially to the fishig ports.In consequence,a study of typhoon's effect on the hydrodynamic field of fishing ports and the spatial distribution of overflow,shipping capsizal and drag in fishing port during the typhoon landing process has meaningful application values to the fishing port emergency commands and the reduction of fishery losses.This paper innovatively improves an orthogonal concentric circle grid for the storm surge and wave delft3d model to get a high precision simulation result in small scale fishing port under the codition of large area typhoon storm surge.Which bings in the advantages of wide coverage,high resolution,excellent aspect,fine orthogonality and smoothness,high calculation precision and quick calculation speed.The concentric circle grid delft3d model is used in the coupling simulation of the typhoon storm surge and the wave in Dongtou fishing port during NO.1211,NO.1323,NO.1419 and NO.1509 typhoon process.The simulations of storm surge were in good agreement with the measured data,and the computed wave peak were also close to the field value.And then the temporal and spatial distributions of water level,flow velocity and wave height of dongtou fishing port during the different path of typhoon process were simulated by the model.The results show that:The typhoon whose landing position was at the right radius of maximum wind had the biggest comprehensive effect on the wave height in Dongtou fishing port.While,the typhoon of which landed at the left radius of maximum wind of fishing port had the biggest comprehensive effect on the water level,storm surge and flow velocity in Dongtou fishing port.Thanks to the passing direction perpendicular to the shoreline,the typhoon came from southeast had the biggest comprehensive effect on the water level in Dongtou fishing port.Because the northward typhoon was beneficial to the wave incoming through the west gate,it had the biggest comprehensive effect on the wave height.And the typhoon came from east had the biggest comprehensive effect on the flow velocity due to the similar direction with the current.In addition,both the wave scale and current velocity of northwest typhoon were strong enough,typhoon with this path has the maximal comprehensive effect.The risk of overflow,capsizal and drag in Dongtou fishing port during the typhoon landing process was analysed based on the simulation of temporal and spatial distribution of storm surge,flow velocity and wave height in the port during the typhoons level from 12 to 17 with the direction from southeast and landing on the left of dongtou fishing port.The analysis shows that as the dike of Jiucaiao to the south of port is the lowest,the overtopping lasted for 70 minutes in level 12 typhoon means that area doesnot have the preventing abilities.The risk of capsizal seems high in Dongtou fishing port,even in the condition of level 12 typhoon,the anchor area was less than 0.3 km2,concentrating around the small Beiao.At the meantime,the available anchor area mainly distribute near the Banpinshan shore and in Shiziao,about 1.521 km2 under level 12 typhoon.