ESTIMATION OF SHOALING FOR PROPOSED CHANNELDEEPENING IN AN ESTUARY, MATAGORDA SHIP CHANNEL, TEXAS, USA

摘要

The Matagorda Ship Channel is proposed to be widened and deepened from its presentdimensions of 61 m bottom width and 11 m mean low tide depth (local navigationdatum) to 122 m bottom width and 13.4 m depth for the estuarine portion of the channel.An anticipated response to the widening is an increased sediment shoaling rate in thechannel, thereby increasing the maintenance dredging rate. Potential sources of sedimentcontributing to the shoaling, including ship wake, have been identified. A field datacollection program was conducted and a numerical modeling analysis initiated tounderstand the sediment pathways, estimate future shoaling rates, and provideinformation to manage the dredged material. Preliminary results indicate that channelshoaling by ship wakes is small and may contribute only 5% of the annual shoaling.