Study and analysis of siltation at nahre ghasr fishery port
23 Jun 2017-Vol. 1, Iss: 35, pp 36-36
TL;DR: In this paper, the main flow mechanisms that can affect the rate of siltation including the horizontal exchange, the vertical exchange and tidal filling, were analyzed and shown that tidal filling plays the dominant role on the sedimentation at Nahre Ghasr channel.
Abstract: The discharge of Arvand River and tidal currents affect the large siltation at Nahre Ghasr Fishery Port, located at the Nahre Ghasr channel, the Persian Gulf. Using 2DH and 3D numerical models, the flow pattern at the channel was investigated to study the details of siltation problem. The local model was calibrated by the measured data of water surface and suspended sediment rate. The main flow mechanisms that can affect the rate of siltation including the horizontal exchange, the vertical exchange and tidal filling, were analyzed. The study showed that tidal filling plays the dominant role on the sedimentation at Nahre Ghasr channel. Different scenarios were also examined for reducing the siltation rate at the port.
References
More filters
TL;DR: In this paper, a relocatable system for generalized inverse (GI) modeling of barotropic ocean tides is described, where the GI penalty functional is minimized using a representer method, which requires repeated solution of the forward and adjoint linearized shallow water equations.
Abstract: A computationally efficient relocatable system for generalized inverse (GI) modeling of barotropic ocean tides is described. The GI penalty functional is minimized using a representer method, which requires repeated solution of the forward and adjoint linearized shallow water equations (SWEs). To make representer computations efficient, the SWEs are solved in the frequency domain by factoring the coefficient matrix for a finite-difference discretization of the second-order wave equation in elevation. Once this matrix is factored representers can be calculated rapidly. By retaining the first-order SWE system (defined in terms of both elevations and currents) in the definition of the discretized GI penalty functional, complete generality in the choice of dynamical error covariances is retained. This allows rational assumptions about errors in the SWE, with soft momentum balance constraints (e.g., to account for inaccurate parameterization of dissipation), but holds mass conservation constraints. Wh...
3,133 citations
TL;DR: In this paper, the authors investigated the feasibility of a current deflecting wall (CDW) for other harbor basins in Hamburg, experiments for the Parkhafen were carried out in a nondistorted physical scale model.
Abstract: Sedimentation in harbor basins necessitates continuous maintenance dredging to keep the bed level of the harbor at the desired depth. Costs involved in the dredging and disposal of the material are often significant, and Port Authorities therefore search for adequate methods to mitigate the influx of sediment into harbors. In the 1990s, a current deflecting wall (CDW) was constructed in the entrance of the Kohlfleet harbor in Hamburg. Field observations on dredging volumes showed that siltation in the Kohlfleet could be reduced by about 40%. To investigate the feasibility of a CDW for other harbor basins in Hamburg, experiments for the Parkhafen were carried out in a nondistorted physical scale model. Water exchange between the Parkhafen and the river Elbe is governed by tidal effects and horizontal entrainment and possibly sediment-induced density currents. The first two effects were addressed in the hydrodynamic scale model. Various design parameters, such as curvature, length, and location of the CDW, were investigated under steady state as well as tidal conditions by means of visual observations of float tracks and dye injection to arrive at an optimum configuration. The spreading of dye was assessed with digitized video images, which were analyzed in terms of dye concentrations. This technique appeared to be very adequate, as high-resolution spatial information was obtained. From the dye experiments under steady state conditions, it was concluded that with the selected CDW design it is possible to reduce the gross inflow of river water into the harbor by 25-45%. The application of a sill, connected to the upstream side of the CDW, may contribute another 10% as near-bed water with high suspended sediment concentration is deflected into the river. The tidal filling of the harbor is then accomplished with water carrying a reduced sediment load.
22 citations