Structural Methods to Reduce Navigation Channel Shoaling

摘要

Shoaling of harbors and navigation channels is a global problem. Expensive dredging operations must be undertaken to remove accumulated sediment and maintain navigable depths to continue uninterrupted navigation. Since the draft of commercial vessels and oil tankers is continually increasing, the navigation channels are getting wider, deeper and longer, thus requiring greater maintenance dredging. The length of a navigation channel depends upon the local geographical configuration and it may vary from less than a mile to 50 miles or more. It is absolutely essential to determine the important factors at play before considering an appropriate method for reducing siltation in navigation channels. These factors include: type of sediment, identification of sediment source, critical natural parameters involved, time scale of shoaling occurrence, and total volume of sediment. The types of available measures include reduce/prevent/catch/divert sediment inflow from the source, and prevent sediment recirculation/deposition. These methods may also be classified alternatively as structural methods, nonstructural methods, and management/other methods. The best-suited option for a given project must be well studied in advance to ensure its efficient functioning for the intended purpose. Sometimes, a combination of various methods may have to be used.