1990 by CRC Press, Inc. The estimation of various parameters involved in numerical modeling of hydraulic systems is discussed. The method described here uses the adjoint equation approach, which has also been used in ground-water hydrology, with the strong constraint formulation in the relevant functional. The parameter-correction equation is used to modify parameter estimates, with the philosophy that there is no modification when the data misfit vanishes. The application to a set of equations (e.g., equations of motion) is illustrated. In particular, this dataassimilation method is used to determine the friction factor for tidal rivers. The method is thus an alternative to those suggested by Dronkers,17Yeh and Becker,18or Chiu and Isu19.
