Mathematical modelling of Shing Mun River network

Abstract This paper implements an accurate as well as efficient solution to the non-linear de Saint-Venant Equation describing unsteady open channel flow. The time history of stages and discharges within individual segments in any channel can be simulated in a connected, essentially one-dimensional network, subject to initial and boundary conditions. The mathematical model developed is based on the 4-point operators Preissmann implicit finite difference scheme and is tailored for use on the IBM/PC/XT or PC/AT microcomputers preferably with 80287 numeric coprocessor chips in place. The program is written in FORTRAN and is compiled by PC software Microsoft FORTRAN version 4.0. Real hydraulic features, including branched channels and ‘tidal flats’, are simulated. The model is subjected to carefully chosen analytical test problems which embrace many essential realistic features of coastal hydrodynamic applications. Excellent agreement is recorded with the analytical solutions. The model is applied to study the tidal dynamics and potential flood hazards in the Shing Mun River network. Hong Kong.