Abstract: Physical laws are fundamental to natural systems across many fields in environmental science. For example, a study of fluid dynamics can be used to describe the dispersion of water pollutants. In this study, the best-fit model was produced to predict spatial sedimentation rates at Loagan Bunut Lake. The lake is a flood plain lake that is located within the boundaries of Loagan Bunut National Park in the northeast part of the state of Sarawak. Twenty-two cylindrical traps were installed at the lake. The traps were placed in November 2005 until April 2008. Each sample was collected after about four to five months of deployment. A dry sedimentation rates and linear distances from Trap 1 located at the confluence of Bunut River were measured. Based on strong coefficient of determinant, the best-fit model of sedimentation rates distributed by advective force at the distance 0-600 m from Bunut River was S = So e-kx or S = So e Rx/ws. Reynold ’s theorem of mass flux was used to explain coefficient k in the equation.