HYDRODYNAMIC RESPONSE OF A TRANSGRESSIVE SHOAL TO THE PROPOSED MINING FOR RESTORING ADJACENT BEACHES AND BARRIERS: SABINE BANK, OFF LOUISIANA-TEXAS COAST, UNITED STATES

Sabine Bank, a transgressive shoal located 30 km off the Louisiana-Texas border, USA, has been considered as one of the plausible resources for re-nourishment of the adjacent barrier islands and beaches. Little has been reported on the bottom boundary layer dynamics and sediment transport from this shallow coastal environment. A comprehensive field investigation, coupled with numerical modeling, has been implemented. Wave and bottom boundary layer interactions were strongly associated with the passage of cold fronts across the region. Strong southerly/southeasterly wind regimes also contributed to the re-suspension and transport of sediments, even during summer season. Modification in bulk wave parameters due to two mining scenarios were computed using modified bathymetries and the result shows minimum impact from the proposed mining from the shoal crest. Sediment re-suspension intensity (RI) was computed and found to be high over the inner shelf and shoal during severe storms.