非饱和土水特征曲线模型参数反演辨识研究

Study on model parameters identification of unsaturated soil water characteristic curve

建立了非饱和土壤水分传输的控制方程,采用Levenberg-Marquardt方法分别对土壤水分特征曲线Van-Genuchten模型和Brooks-Corey模型中的相关参数进行反演辨识,得到了模型参数的最优估计值。数值结果表明:采用Van-Genuchten模型得到的粉砂土壤水分特征曲线均能够较Brooks-Corey模型更好地反映土壤水力特性,且Van-Genuchten模型与实测值具有很好的一致性,从而验证了数值反演辨识方法的有效性。

A one-dimensional unsaturated soil moisture transport model has been established.The model parameters of soil water characteristic curve are obtained by adopting Levenberg-Marquardt nonlinear parameters optimization method.The optimal estimation values to inverse the model parameters is given.Numerical results show that Van-Genuchten model has better flexible than Brooks-Corey model for describing soil hydraulic properties.The identification of hydraulic functions yielded unique and reasonable estimates.The optimized values by numerical method in this paper is in good agreement with experimental data,and the comparison analysis validates the reliability and practicability of numerical identification method.