风暴潮与天文潮非线性相互作用的理论分析

Nonlinear interaction between storm surges and astronomical tides

对一维狭长半封闭水域中的风暴潮与天文潮非线性相互作用问题进行了研究,并用摄动方法求出了纯风暴潮增水ζS、天文潮增水ζT及风暴潮与天文潮非线性相互作用形成的增水ζST的一阶近似解析表达式.通过三者表达式的分析,直观地讨论了浅水效应、非线性效应在风暴潮与天文潮非线性相互作用中的影响.结果表明,浅水效应对增水水位起主要作用,非线性效应对增水的作用取决于波幅与水深比值的量阶.

A perturbation analysis was performed to solve the one-dimensional nonlinear equation of the interaction between storm surges and astronomical tides in a long and narrow semi-closed sea region. The one-order approximate analytical expressions for the set-up of pure storm surges ζ_S, the set-up of astronomical tides ζ_T and the set-up of ζ_(ST)induced by nonlinear interaction between storm surges and astronomical tides were derived. From the analysis of the expressions, it is concluded that the shallow water effect and the nonlinear effect play different roles in the nonlinear interaction between storm surges and astronomical tides, that the set-up water level is mainly affected by the shallow water effect, and that the contribution of the nonlinear effect to the set-up water level depends on the order of the ratio of wave amplitude to water depth.