采用受控的自回归滑动平均模型(CARMA)分别研究了珠江河口洪、枯季对外海潮波响应的固有频率。枯季采用单输入单输出模型,洪季采用双输入单输出模型,通过验证、检验表明,模型(CARMA)可用于寻求复杂网河对外海潮波响应的固有频率,方法可靠,易操作。通过频率增益响应分析,发现枯季珠江河口的固有频率以浅水分潮频段为主,对应周期介于6-10.0 h之间,枯季固有频率未出现在全日潮波对应的频段。洪季珠江河口的固有频率也以浅水分潮频段为主,珠江河口对浅水分潮的系统增益响应幅值最大。固有频率接近浅水分潮频段的站点,枯季较洪季固有频率减小,对应周期延长。
With the help of the controlled auto-regression and moving-average model(CARMA) based on system and cybernetics approaches,this paper studies the system response of the tidal propagation in the Zhujiang(Pearl)River Estuary(PRE).By system model identification,the CARMA models'parameters of the single-input single-output(SISO) for 59 stations in January 2001 of dry season and the double-input single-output(DISO) for 65 stations in July 1999 of flood season,were established with the tidal elevation and river inflow in the PRE.Frequency response analysis based on the system models provides some important insights into the PRE dynamic system.It is found that the nature frequency of PRE both in dry season and flood season are almost at the shallow water tidal bands with period 6~10 h.The experiments proved the nature frequency of resonance found in PRE were dependable,and also clarified that the response approach based on system and cybernetics can help us find the periods of resonance of the estuarine dynamical system.