Prediction–Correction Method for Parallelizing Implicit 2D Hydrodynamic Models. II: Application

Abstract

AbstractA two-dimensional (2D) hydrodynamic model is developed for the Jing-Dongting river–lake system, with the computation domain (3,900 km2) covered by a channel-refined grid of 300,000 cells. The model provides good descriptions of the river–lake characteristics (strongly coupled, annular branches, varying flow regimes). In a simulation of a 1-year unsteady flow process, the mean absolute error in simulated water levels is 0.11–0.15 m, and the mean absolute relative error in simulated cross-section discharges is 4.3–8.5%, compared with field data. The accuracy of the 2D model is obviously better than those of existing one-dimensional (1D) and 1D–2D nested models. The prediction–correction parallelization (PCP) method is then tested by simulating the river–lake system using 64 subdomains. The complexities of real rivers are revealed to have almost no negative effects on the quasi-coupled solutions and accuracy of the PCP method. In tests, the mean absolute error in water level is found to be approxima...