Hydrodynamic and transport model of the Siak estuary

Abstract

The Siak River flows around an industrial area of Riau Province, Sumatra (Indonesia) towards the Malacca Strait. Most of domestic and industrial wastes are transported along this river to the estuary. In this investigation, the HAMburg Shelf Ocean Model (HAMSOM) and an attached dispersion model are employed to simulate the circulation patterns and the dispersion of pollutants, respectively. In this study the pollutants are released only in the front of Siak river mouth. The simulation is performed for the period from January 2001 until May 2006, and the results are validated with available observations and satellite data. By means of this model study, it is shown that although the wind direction changes with the monsoon, the direction of the surface currents in the Malacca Strait are almost the same over the entire year. Results of the transport model suggest that most of the pollutants are transported through the Bengkalis Strait to the north into the Malacca Strait. Although the general circulation pattern in the Malacca Strait does not show a seasonal reversal, it could be demonstrated that the monsoon cycle influences the transport and dispersion of the pollutants significantly.