Port Qasim navigation channel is located in the Indus Delta for passes through a highly active coastal zone as well as an extensive mangrove creek system. The channel suffers from high annual siltation and significant seabed movements in the coastal zone, leading to high annual maintenance costs and navigational difficulties. In addition the existing channel is insufficient for the projected traffic in terms of both depth and vessel numbers. As a result Port Qasim Authority wished to deepen and widen the channel and to identify ways in which to mitigate ongoing channel siltation in order to reduce annual maintenance dredging requirements. Channel improvement options that were identified and assessed included the deepening of the channel, the introduction of passing places, widening the channel and introducing navigation along an alternative existing creek. Mitigation measures that were investigated included the introduction of training wall, realignment of the channel within the coastal zone and the adoption of a reactive approach to maintenance dredging. Options were assessed in terms of interaction with coastal processes and economic returns. Key aspects of the study were the numerical modelling the identification of the hydraulic regime in the navigation and surrounding creek system, the morphological processes in the coastal zone, the assessment of likely impacts of each option on channel siltation and the preparation of a clear channel development master plan.
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