Research And Application Of Water Quality Model For Tidal River Networks

With the much focus and financial support on the water environment regulation, it is become more and more important to study the flow movement and water quality change in river networks under tidal influence. Through the numerical method, flow movement and water quality can be analyzed, and it is major part for analysis the objectives of water pollution control planning. This paper is focus on the water environment in plain river network controlled by gates areas. Based on the comparison between available water quality models for plain river network areas, WASP5 system was selected by as the basic simulation tool. According to hydrodynamic features of water body within a tidal river network controlled by gates, a one-dimensional hydrodynamic model is developed in which Preissmann weighted implicit scheme is used. Further, a coupling model of hydrodynamic model and water quality model was developed and it can be applied to simulate the water environment of a tidal river network controlled by gates.The main contents discussed in this paper are as follows:①In accordance with the complexity of tidal river network controlled by gates, make a comparison and choice among available water quality models for plain river network areas.②Based on Saint-Venant equations, a one-dimensional hydrodynamic model is developed in which Preissmann weighted implicit 4-points scheme is used. Apply river method model to solve the linear algebra equations. ③Use WASP5 to simulate the water quality of tidal river network controlled by gates. And optimize WASP5 model in accordance with the specific characteristics of tidal river network. ④Develop a coupling model of hydrodynamic model and water quality model. Put the hydrodynamic parameters which was derived from hydrodynamic model into WASP5 water quality model, and then concentration of all water quality variable can be known. ⑤Use Mapinfo to make the result of computation in visual form, which benefits for the management to manage in fast, convenient and accurate way.