Procedure to Calibrate and Verify Numerical Models of Estuarine Hydrodynamics

Abstract

In most hydrodynamic models, friction and turbulent diffusion/dispersion coefficients are the important calibration parameters affecting the calculation of surface elevation, velocity and salinity distribution. This paper presents a rational approach to calibrate and verify a hydrodynamic model of partially stratified estuaries. The calibration procedures and verification requirements are demonstrated with the application of a vertical (laterally averaged) two-dimensional model to a branched estuarine river system. The friction coefficient is calibrated and verified with model simulation of barotropic flow, and the turbulent diffusion and dispersion coefficients are calibrated through comparison of salinity distributions. The overall model verification is suggested to be achieved with comparisons of Eulerian residual circulation and salinity distribution. In the case of the Tanshui River system, the available prototype current records are too short to calculate slowly varying residual currents. The snapshots of the model-computed and field-measured residual currents are provided to qualitatively agree with theoretical analysis. The overall performance of the model is verified with an additional set of salinity data.