An Implicit Coupled 1D/2D Model for Unsteady Subcritical Flow in Chan-nel Networks and Embayment

作者：GENG Yan-fen,WANG Zhi-li

摘要：In this study, 1D and 2D shallow-water models were coupled to simulate unsteady flow in channel networks and embayment. The 1D model solved the 1D shallow-water equations (St. Venant) using the Preissmann box method and targeted long narrow reaches of the river networks, while the 2D model targeted broad channels and embayment and solved the 2D shallow-water equations using a semi-implicit scheme applied to an unstructured grid of triangular cells. The 1D and 2D models were solved simultaneously by building a matrix for the free surface elevation at every 1D junction and 2D cell center. Velocities were then computed explicitly based on the results at the previous time step and the updated water level. The originality of the scheme arose from a novel coupling method. The results showed that the coupled 1D/2D model produced identical results as the full 2D model in classical to benchmark problems with considerable savings in computational effort. Application of the model to the Pearl River Estuary in southern China showed that complex patterns of tidal wave propagation could be efficiently modeled.

发文机构：School of Transportation State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering

关键词：1DRIVERnetworkMODEL2DUNSTRUCTUREDMODELfullcouplingMODELPEARLRIVERDelta

分类号： P73[天文地球—海洋科学]