运用WKBJ型摄动逼近法 ,对环境流同沙纹海底共振产生的自由表面水波的非线性效应进行了研究·　沙纹海底由缓变平均水深部分和快变海底部分叠加构成·　根据对快变海底波长的不同选取 ,可以相应地激发环境流同非平整海底的同步共振、超谐波共振和次谐波共振 ,由此产生自由表面波运动·　对次谐波共振进行了详细考察·　对于定常流自治动力系统 ,对可能出现的非线性各种稳态及其稳定性进行了探讨·　假如环境流具有一个小振动分量 ,动力系统成为非自治的 ,则将发生混沌现象· The WKBJ type perturbed approximation method is used to study the nonlinear effect of environmental surface wave and free surface water wave generated by the seafloor resonance. The sandy seafloor is formed by the superposition of the slowly changing mean depth and the fast changing seafloor. Different selections of seafloor wavelengths can correspondingly stimulate the simultaneous resonance, the superharmonic resonance and the sub-harmonic resonance of the environmental flow with the non-flat seafloor, thereby generating free surface wave motion. A detailed examination of the subharmonic resonance has been made. Flow Autonomous dynamical systems to investigate the various nonlinearities that may occur and their stability. If there is a small vibrational component of the environmental flow and the dynamical system becomes non-autonomous, chaos will occur