Wave transformation over Sabine Bank, off the Louisiana-Texas coast: Implications of targeted sand mining for coastal restoration

摘要

Sabine Bank, a transgressive shoal located 30 km off the Louisiana-Texas border, has been identified as a viable source for restoring the storm-ravaged coasts nearby. Wave-climate for the coast is characterized by a low-energy regime with average SWH less than 1 m and mean wave direction from south-southeast. A fully spectral MIKE 21 wave model has been implemented for the first time for this coast to study the wave transformation over the Sabine Bank. The model was implemented on a high resolution grid to study the modification in bulk wave parameters due to two proposed mining scenarios, and results show minimum impact from restricted dredging of the bank crest. Wave induced sediment re-suspension intensity (RI) was computed and found to be high over the inner shelf and shoal during severe storms. For storm weather conditions, the shallower western portion of the bank dissipates waves significantly, a trend reflected in the computed RI values also. The utilization of material from the bank has a very high potential for use in future restoration projects along the western Louisiana-Texas coast.