WATER QUALITY SIMULATION OF TE-CHI RESERVOIR USING TWO-DIMENSIONAL MODELS

The application of a two-dimensional laterally averaged hydrodynamics model (LARM2) and a water quality model (WASP3) for the study of eutrophication problem in Te-Chi Reservoir in Taiwan is presented. The models were first calibrated and validated with field temperature and water quality data. The combined models were then used to characterize the temperature distribution, seasonal overturning phenomena, and the variations of chlorophyll-a, organic nitrogen, ammonia nitrogen, nitrate nitrogen, organic phosphorus, inorganic phosphorus, and dissolved oxygen in the reservoir. It was shown that the limiting factor for eutrophication in Te-Chi Reservoir is phosphorus, and that better control of phosphorus loading into the reservoir is the crucial step toward improving the water quality of Te-Chi Reservoir.