With the improvement of living standard and the increase in populations, the demand for quality environment and water supply is increasing, which requires better understanding, engineering and management of our limited and deteriorating water resources. Tools are therefore needed to study water flow in rivers, lakes, reservoirs, and coastal zones, as well as water associated processes of flooding, soil erosion, sediment transport, landscape changes, pollutants and containments transport and their effects on the quality of water, ecology, and environment. Traditional tools such as laboratory experiments and field measurements generally cannot meet this demand due to their high cost and long turnaround time. Water flows and these processes can be simulated using computational models, because these physical and chemical processes can be described by mathematical and empirical equations and solved using computer programs. A larger number of computer programs are developed and assembled to..