Author(s): K. Yoshida; T. Ishikawa
Linked Author(s):
Keywords: Inverse estimation; Bed roughness; Flood plains; Shallow-water adjoint model
Abstract: This paper describes the methodology on an inverse estimation of distributed bed roughness coefficients of open-channels with flood plains. A Lagrange multiplier method is employed for the parameter identification. A shallow-water model is utilized as the constraint condition, and a variational approach enables us to develop the adjoint model. The requisite gradient information to satisfy the optimal condition is efficiently obtained through the adjoint equations. The optimal coefficients are determined by a quasi-Newton method. The identical twin experiments were carried out by using the synthetic data in order to verify the validity of the proposed method. The assimilated data consist of the water level and the depth-averaged velocity calculated by the shallow-water model. The obvious finding is that the coefficients can be accurately predicted and these estimates are stable with respect to random noise in data, if sufficient data are available at more observation stations.
Year: 2011