Park, E.-J.; Yu, K.B.; Ku, C.Y.; Psuty, N.P.; Kim D., and Shin, Y.H., 2012. Short-term sedimentation processes and accretion rates in the Sunchon Bay estuarine marsh, South Korea.

Spatial variations in sedimentation during individual tidal cycles were investigated using filter paper traps. The mean mass of sediment deposited in each tidal cycle was higher at the levee edge than at the inner marsh. The mass of sediment decreased with distance from the head of the estuary. There were weak relationships between tidal regime and sediment accumulation. Spatial variations of annual accretion rates were investigated with marker plots. The annual accretion rate at the inner marsh was higher (1.5 to 3.5 cm/y) than that at the tidal river levee edge (0.8 to 3.0 cm/y). Total suspended sediment (TSS) concentrations in the tidal water column indicated that the accretion rate was affected by vegetation. TSS concentrations in the water column leaving the vegetation cover during ebb tidal flows dramatically decreased. There were strong relationships between the concentration of suspended load and accretion rate. The spatial pattern of sedimentation processes at different timescales was mostly due to erosion of the levee edge by tidal flow. The major findings are: (1) The spatial patterns of sedimentation processes at various timescales are different, (2) vertical accretion rates ranged from 0.9 cm/y to 3.5 cm/y, (3) the study area has a depositional regime over the timescale of the present data, (4) the mean and minimum deposition rates in the study area are higher than other cited systems, and (5) the high accretion rate of this area is related to human-induced environmental change, and the sedimentation trajectory is now evolving to a new equilibrium.