A Two-Dimensional Model for Water Quality Simulation in lakes and its Aplication to Tabiishidani Lake in Sasaguri : Fukuoka Prefecture,Japan

The objective of the research is to ubild a two-domensional, unsteady, laterally averaged model for simulating water quality in lakes. The model consists of circulation of flow fields and water quality simulation in lakes. The main foundation of the model is two-dimensional equations of the incompressible Navier-Stokes equations simulation and diffusion equations for water quality simulation. These equations were doscretized by the finite volume method(FVM) and were solved for flow field velocities and water quality variables respectively by the SIMPLE(Semi-Implit Method for Pressure-Linked Equations) algorithm (Patanlar, 1980) with the variables defined on a space- staggered grid. To solve these equations effectively, a numeral method has been developed and coded in Fortran 90 (Nyhoff and Leedtma, 1997;1999) with using the Tri-Diagonal Matrix Algorithm (TDMA). To vertify the model, Tabiishidani lake, which is water temperature, the size of cross-sections of the lake and meteorological data have been collected and used as the initial and boundary conditions for the model. After calibration, the model was applied to simulate water temperature was chosen to illustrate the mothodology. Howecer, this model can be extended to simulate any variable of water quality in lakes. The results of this research indicate that this model can be a useful tool for simulating water quality in lakes