Explanation: Kolkata, located in West Bengal, is a significant port city in India. The port of Kolkata is classified as a tidal port, which means that its operations are influenced by the tides of the sea. The Hugli River, a distributary of the Ganga, is the primary waterway for the port. The Hugli River flows through the city of Kolkata and connects it to the Bay of Bengal.
Tidal ports like Kolkata face unique challenges due to the tidal nature of the waterway. One of the most significant challenges is sediment accumulation. As the river flows and the tides ebb and flow, sediment is deposited in the riverbed, which can reduce the depth of the waterway. This sedimentation can make it difficult for ships to navigate, especially larger vessels that require deeper water to pass safely.
To address this issue, regular dredging operations are necessary. Dredging involves the removal of sediment from the riverbed to maintain a navigable depth. This process is crucial for ensuring that the port remains functional and can accommodate the various sizes of ships that use it. The Hugli River, being the primary waterway for the port, is the focus of these dredging operations.
It is important to note that while the Ganga is a major river in West Bengal, the specific context of the question pertains to the Hugli River. The Ganga itself does not directly serve as the waterway for the Kolkata port. Other rivers mentioned, such as the Mahanadi in Odisha and the Brahmaputra in Assam, are not relevant to the context of the Kolkata port and its dredging needs.
In summary, the Hugli River is the critical waterway for the port of Kolkata, and regular dredging is necessary to maintain navigable depths due to the tidal nature of the river and the sediment accumulation that occurs. This makes the Hugli River the correct answer in the context of the question.