Han River estuary stretches from the land to marine wetlands, and is the only one among the four river estuaries in the country where no tidal barrage is being built. Recently, there have been discussions on the conservation of the Han River Basin. Due to the increasing heavy summer rainfall in recent years, there has been more erosion-sediment transport and flooding which not only play as an important factor in the direction of the Han River Basin but also in the status of the ecosystem of the Han River estuary. However, there lies a problem in the area of data collection. As the Han River estuary is located in the trans-boundary of North and South Korea, it is often difficult to have a collection of good observation data of the physical characteristics and tidal data under the influences like hurricanes and winter ice. In order to solve this problem, a two-dimensional flow analysis model is developed to investigate the hydraulic and sediment transport behaviors with variation of river bed, in the effort to analyze and predict the tidal levels. For the accuracy verification of the model, a direct integration and direct step calculation of the hydrograph will be computed and compared against the numerical simulation results where the acceptable error rate is within 1%. For the analysis, the discharge from the events of dry season and heavy rainfall in 2002 is fed into the calibrated model. The analysis results showsthat all the targeted regions were affected by tidal level and the low tides are shown to be the dominant factor for affecting the water level.