The aim of this paper is to compare the ability of two numerical models to simulate two-dimensional dam-break flows. Dam-break modelling is important in reducing the high-risk of dam failure by determining the water flow movement and its effect on buildings downstream. In this study, the Taylor Galerkin and Forward Time Central Space method is presented to simulate 2-D dam-break flow. The Hansen filter is applied to both methods to reduce numerical instability oscillations in the model. The filters were used for each time step at each computing point. The model is verified by comparing the result simulation with numerical results from previous studies. The result show that Taylor Galerkin numerical scheme with Hansen filter is successful to simulate the problem of 2-D dam-break. Also, the Taylor Galerkin model has better results than the FTCS model. Studies like this are needed for mitigation efforts in the event of dam failure.

The potential hazard of dam construction is the possibility of dam failure. Dam failure will cause damage to property and the environment, as well as loss of human life. In addition, the dam-break flow also causes erosion and sediment transport which can affect the morphology of rivers around the dam. Dam-break flow analysis is needed to minimize the potential hazards of dam construction. Dam-break flow analysis can be done by performing numerical modeling. This study develops a numerical model using the Taylor Galerkin method. The Taylor Galerkin model is used in simulating the dam-break flow along with the sediment transport that occurs. Mathematically, this flow is generally expressed by the shallow water-Exner equations. The shallow water equations describe the movement of water, and the Exner equation describes the movement of sediment. The model will use the Galerkin method for spatial derivatives and the Taylor series approach for time derivatives in this study. A numerical filter by Hansen was also added to the model to overcome the instability of the model due to numerical oscillations. To determine the performance of the Taylor Galerkin model, simulation results were compared with experimental data and other numerical results from previous studies. The Taylor Galerkin model can simulate the dam-break flow with sediment movement over a movable bed well based on this study. Studies like this are needed to reduce the high risk of dam failure.

A study of the tides in the river has been carried out in this paper. The rivers studied are the Jawi River (Kakap) and the Nipah River. The two rivers are located in Kubu Raya Regency, West Kalimantan. This study aims to determine the type of tides and water level elevation in the two rivers. This study uses the Admiralty method to analyze existing tidal data. This method is commonly used in tide analysis. The results show that the tidal type of the Jawi River is a diurnal tide. The water level in the Jawi River is HHWL of 1.4 m (+0.86 m from MSL) and LLWL of –0.319 m (-0.859 m from MSL). Meanwhile, the tidal type of the Nipah River is a mixed tide prevailing diurnal. In addition, the water level is HHWL of 1.167 m (+0.82 m from MSL) and LLWL of –0.473 m (-0.82 m from MSL). This study is expected to be helpful as a reference for infrastructure development in the research area.