Experimental Study on Head of Saline Density Current Affecting by Vegetation

Document Type : Research Paper



     Density currents are the most important transport mechanisms and deposition of sediments which causes sediments transportation to the near of dam body. Therefore, Studying of these flows and their affecting parameters are very important in terms of water quality and pollution prediction .According to density current complexity, experimental studies are typically used. In the present research, behavior of the saline density current forehead flowing over artificial vegetation was studied by conducting experiments. Density currents were entered into the flume with four different concentrations. Artificial vegetation was placed in the direction of the flow with four heights and five densities. Velocity and vertical concentration profile were measured in 6 and 3 longitudinal sections, respectively. The results showed that the most effective artificial vegetation density and height in this work can be concluded 1.4 percent and 0.2 meter, respectively. Keolegan coefficient is presented for velocity calculation of flows over smooth bed and bed with artificial vegetation, according to the vegetation density and height. Finally ,a relationship was provided to calculate the velocity of flows over the beds with artificial vegetation.