An in-situ observational study was conducted to understand the sediment transport processes disturbed
by the flood generation type of Sihwa tidal power plant (TPP). A surface mooring was deployed in Lake
Sihwa (inside of TPP) to collect time-series data of the current velocity and suspended sediment concentration
(SSC). A TPP with a capacity of 254 MW has four sequential phases (power generation
estandbyedrainestandby) of operation. The SSC during power generation was one order of magnitude
higher than that during drain, which led to heavily unbalanced sediment fluxes. The total residual
sediment flux was always negative (into the lake), which was attributed to the mean advection processes
associated with the discharge. Over 18 day mooring period, 78.28 tons m1 of sediment was delivered to
the lake. The source of delivered sediment might be attributed to more local resuspension than the
sediment inflow through the gates of TPP. Since the maximum sediment influx during power generation
occurred within the water head difference of 4e6 m, the reduction in discharge rate can be a possible
measure for solving the sediment accumulation within Lake Sihwa
