Research On Water Flow & Water Quality Numerical Model Of Tide River With Mobile-bed & Complex Boundaries And Its Application

Considering the kinematical characteristics of Pearl River Delta and based on the previous studies by other researchers, a non-coupled 2-D mathematic model for flow, sediment and salinity is presented with staggered body-fitted grids in the orthogonal curvilinear coordinate for complex boundary rivers. The Double-Sweep-implicit finite difference scheme is adopted to solve the momentum and continuity equations of flow motion and the substance transport equation is solved by Alternative-Direction-Implicit method. The present schemes have many advantages such as yielding more accurate numerical results, having high resolution, being well suitable and so on. "The water depth margin technique" is applied to solve the problem of moving boundary caused by varied water level. The model adopts the technique of grouping granule for unsteady and non-homogeneous sediment model and a formula for the interchange between suspend sediment and bed materials is developed in view of the relations of flow carrying capacity and bed-load sediment, it simulates well the physical process in theory. And the research with the measured data of typical hydrology is made, the studies show that the model adjustment and verification were performed in conjunction with field data. The simulated results coincide well with measured data. And the basement for the farther research is founded.