长江口台风增水的数值试验

Numericall Tests on Typhoon Set-up of Yangtze Estuary

对影响长江口区的多次台风的检验表明,气压场分布的高桥模式优于其它模式。台风参数宜采用随台风的移动而变化的数值。在近岸,地形复杂,数值计算网格不宜过大,计算中必须计入非线性项。对长江口区计算域采用三种网格尺寸嵌套的计算结果更接近于实际的增水。为进一步发挥风暴潮数学模型在防灾减灾中的作用,研究增水与潮汐非线性耦合的规律,建立包括潮汐因素的综合模型是重要的内容。

It has been proved,through many tests on Typhoon influencing the region of the Yangtze Estuary,that the Takahashi model is better than others in describing the distribution of atomosphric pressure.It is suitable to adopt typhoon parameters varying with the motion of typhoon.In the near shore,which has complicated geometry,the calculating grid mesh should not be too large and the non- linear term must be included in calculation.For the region of the Yangtze Estuary,the results obtained by embedded grid mesh system with three kinds of space steps are comparatively close to the values of real set-up.In order to give full play to the numerieal model of storm surge in the precaution against calamities,it is important to study the nonlinear coupling regularity of set-up and tides,and further- more to establish a comprehensive model including tide factors.