Analysis of Water Quality Impact for Water Intake in Jinyang Reservoir Using CE-QUAL-W2

Hydraulic and water quality models with high reliability are necessary for the efficient management of water quality in the reservoir. The model capacity can be demonstrated by the application for the various hydrological conditions. CE-QUAL-W2 model is laterally averaged two-dimensional hydraulic and water quality model. The W2 model, which is suitable for the narrow reservoir like the Jinyang reservoir as compared with the depth and length of waterbody, has been frequently used by many researchers. Namgang watershed is expected to increase the water demand. In this study, the W2 model is validated under two different hydrological conditions; wet year (2011) and normal year (2009). Using hydrological and water quality condition for calibration, 2011, the effect of water intake increase was simulated. The simulation results showed that the increase of water intake led to increase the concentrations in total nitrogen, total phosphorus and Chlorophyll- concentration. Especially the concentration increase was appeared during the dry season in each of up to 62.53% (Total nitrogen), 39.07% (Total phosphorus) and 232.19% (Chlorophyll-). The changes of chlorophyll- is similar to those of total phosphorus concentration.