Studies on dynamics of tides, waves, currents (hydrodynamics) and sediment transports are compulsory for succesful estuarine, coastal, and offshore planning and operation. Such studies employ a set of equations operated as computational numerical models. Computer models allow simulation of estuarine, coastal, and ocean hydrodynamics and sediment transports provided the boundary conditions are known. In this case, accurate bathymetry and tide, as well as wind field and properties of seawate and seabed should be made available.
The benefits of using computer simulation for understanding marine dynamics are its reversibility, cost-effectiveness, integrity of understanding, and visual impression of presentation. One can test several scenario of what-if situations, i.e. what would be the effects of given inputs to the outputs, and analyse the relation, cause-impact, and develop possibilities for solution. It is an effective tool to assist problem solving and decision making. Scenario of daily and extreme ocurrence, as well as possible man-made impacts on can be foreseen.
In order to perform reliable simulation, a model should undergo setup, calibration, and validation. Analysis of sensitivity must be carried out to understand how the model react to given input. Presence of field observation data is compulsory. This provides correct adjustment on how the model should behave and deliver realistics results. Extra set of field observation data should also be made available in order to ensure the validity of the simulation to perform various what-if scenario.