Herman C. Miller, Andrew Salkield
Storm Transport Ocean Rate Measurements Work Unit,
US Army Corps of Engineers, Coastal Research and Development Program
This investigation seeks to quantify total longshore sediment transport during storms. Participation in DUCK94 is expected to provide the opportunity to refine the measurement scheme, evaluate the influence of the pier, and optimize the calibration requirements of the sensors. While the focus will be on preparing for SandyDuck, providing measurements of the volume of sediment moving along shore is the desired objective.
The pier-based Sensor Insertion System (SIS) will be operated throughout the experiment. The SIS is a diverless deployment system that is designed to rapidly install, remove, and relocate sensors along the entire pier length. The SIS can operate in storms with Hmo = 3 m, currents = 2 m/s, and 20 m/s wind speeds.
By DUCK94, the SIS will be instrumented with ten OBS-3 sediment concentration monitors, five 512 electromagnetic current meters, a pressure wave gage, underwater video camera, and two streamer trap sediment samplers. A PC-based data acquisition system will be used to collect the data. It is anticipated that 8 to 16 unused channels will be available for future expansion or co-investigations.
The approach will be to:
a. Evaluate the influence of the pier by comparing the measurements made away from the pier to those made from the pier-based SIS.
b. Refine the spatial sampling scheme by investigating the influence of the number and position of the cross-shore sampling locations on computations of total longshore transport.
c. Refine the temporal sampling scheme by investigating the tidal influence.
d. Compare computations of the total longshore sediment transport based on measurements from the SIS along the pier length, to computations based on measurements made away from the pier during times when the surf zone begins seaward of the end of the pier.
e. Investigate the cross-shore variation in suspended sediment size and its impact on the calibration of the OBS sensors.
FRF staff members Eugene W. Bichner, Brian L. Scarborough, and Charles R. Townsend will assist with the measurements.
For a list of addresses of the investigators involved in Duck 94 click here.