Mathematical modelling of flow circulation and water quality in the Rajjaprabha Reservoir, Thailand | |
| Author | Thana Boonyasirikul |
| Call Number | AIT Thesis no. WA-92-31 |
| Subject(s) | Water quality--Mathematical models Rajjaprabha Reservoir Hydraulics--Mathematical models |
| Note | A thesis report submitted in partial fulfillment of the requirement for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | A multi-layer 2-D depth average mathematical model is applied to simulate the flow circulation and water quality condition in the Rajjaprabha reservoir in June, 1990. The multi-layer approach is used by dividing the reservoir water body into three layers. Each layer is fixed in space and the hydrodynamic condition is governed by the two-dimensional depth average continuity, momentum and dispersion equations. Field data is collected at 6 sampling points in the reservoir and are used as the initial condition and for comparison with the computed results. The thickness of the top and middle layers are set to be 10 meters each to represent the significant variation in the concentration profile of the considered water quality parameter. The remaining depth is considered to be the bottom layer. The computation of hydrodynamic condition between the adjacent layers is connected by the interfacial shear stress for momentum transfer and by the inte1face mass exchange for continuity while the interfacial vertical diffusion is the linking term for the transfer of water quality between the adjacent layers. Due to very small flow velocity during dry seasons, the computed flow condition from the hydrodynamic model is found to have not much influence on the computed water quality from the dispersion model. The considered water quality parameters are iron contents, DO (Dissolved Oxygen) and BOD (Bio-organic Oxygen Demand). The computed concentration is checked with the collected data to verify the model. The calibration of relevant parameters is can'ied out by adjusting the hydraulic and dispersion parameters so that satisfactory results of simulation are obtained. It is found that, due to very small velocities in the reservoir, the model parameter such as ·Manning's n does not have significant effects on the computed flow condition while for the dispersion model the most important parameters that control the dispersion process are the prope1ties of substance namely the settling velocity and the decay rate. Sensitivity analysis has been carried out to determine the effect of model parameters. |
| Year | 1992 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Water Resources Research Engineering (WA) |
| Chairperson(s) | Tawatchai Tingsanchali |
| Examination Committee(s) | Suphat Vongvisessomjai ;Tanaka, Hitoshi |
| Scholarship Donor(s) | Nor Consult International A.S. |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1992 |