spatial and temporal variability of hydrodynamics by the artificial discharge near the inlet of tidal power plant

The Sihwa tidal power plant (STPP) has been operating for last two years. And the repetition of strong inflow and artificial discharge over tidal cycles caused rapid changes in hydrodynamics in the vicinity of STPP. To investigate the effect of artificial discharge on the hydrodynamics, two mooring deployments were conducted near the Sihwa tidal power plant (STPP). The results showed the significant differences of velocity, temperature and salinity under the short-term (flood and ebb) and long-term (spring and neap) time scales. For the short-term time scale, the artificial discharge from the STPP during the ebb tides produced the strong currents (0.8-2.4 m s^-1), resulting in the instantaneous low salinity (28 psu) at entire water column. After the artificial discharge, the velocity changes to the flood and slowly increased (0.2-0.6 m s^-1). The salinity revealed significant peak which associated with backflow. For the long-term time scale, during the spring tide the background salinity was relatively high due to the frequent strong artificial discharge from the STPP, whereas during the neap tide, it was high. Mooring results suggest that the interaction of artificial discharge and tidal modulation has important influences on hydrodynamics.