Silt mitigation measures for a navigational channel in a complex estuary

Abstract

<span style="font-size:12.0pt;mso-bidi-font-size: 10.0pt;font-family:Times;mso-fareast-font-family:" times="" new="" roman";mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-us;mso-fareast-language:ja;mso-bidi-language:="" ar-sa"="" lang="EN-US">Planning of port development projects in a deltaic estuary is a tricky job and it becomes highly complex in the case of determining potential sedimentation and erosion rates in dredged channels. But accurate dredging projections are crucial for economic feasibility analysis in addition to assessing the impact of new structures interfering with the natural processes on the adjacent shoreline and the morphology of the system. Silt mitigation measures are necessary to reduce the siltation in the navigational channels. In this study we consider a range of approaches for evaluating sediment transport for evolving a new navigation channel and necessary silt mitigation measures for harbour planning, and present detailed case from West coast of India. A depth-averaged numerical model for the erosion, sedimentation and transport of cohesive sediment is applied to the estuary. This study is based on the numerical simulation of the mean river discharge and the tidal forcing. The hydrodynamic models were calibrated against field measurements corresponding to the period in which the experimental data were registered. The site described is representative of a very complex coastal environment. The Tapi Estuary in Hazira is a unique dynamic estuary in Gulf of Khambhat on the West coast of India with large tidal range, non-perennial river discharge and high sediment loads of sand, silt and clay presenting challenges for navigation and dredging. The approaches include preliminary site investigations and data collection, basic sediment transport theory, and a range of numerical modeling techniques that can be applied to determine sediment erosion, transport and deposition.</span>