Abstract:

This dataset was collected near Port Fourchon, LA from 2019-09-03 to 2020-01-31. The purpose of this data set was to investigate the effect of waves on marsh accretion. Tropical storm Olga and multiple cold fronts occurred during data collection. Data was collected at two sites, one site was exposed to waves across a large bay, and the other was in a protected tidal channel. At both sites the predominant wetland vegetation was black mangroves.

Suggested Citation:

Esposito, Christopher, Maricel Beltran Burgos, and Diana Di Leonardo. 2022. Vegetation thresholds for sediment transport at Port Fourchon from 2019-09-03 to 2020-01-31. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/XKA817A4

Purpose:

The purpose of this data set was to investigate the effect of waves and vegetation on marsh sedimentation.

Data Parameters and Units:

Water temperature (C) Turbidity (FNU) pH Dissolved oxygen (% saturation and mg/L) Depth (m) Wave height (m) Wave period (s) Accretion (g/cu cm) and accretion rate (g/cu cm/day) RTK Elevation (m) Salinity (PSU) Total dissolved solids (TDS, (mg/L)) Significant wave height (m) Significant wave period (s) Current speed (m/s) Current direction (nautical degrees) Tidal slope (m/hr)

Methods:

Raw data was processed using the software provided with the instrument followed by custom Matlab scripts to remove outlier and obtain hourly averages. Water levels were referenced to NAVD88 using GPS measurements of the water surface during instrument data collection. Atmospheric effects on the YSI pressure sensor were accounted for using measurements of air pressure from a local airport.

Instruments:

Data was collected using several field instruments: YSI multiparameter sonde (water level, salinity, temperature, turbidity, pH, dissolved oxygen), Aquadopp (waves and currents), RBR solo (waves), tiles (sediment accretion). EXO2 YSI - 20 minutes; A YSI was deployed at Site A and at Site C. The YSI at Site A was placed near the intersection of a tidal channel with a larger canal. Site A was very shallow. During the second deployment the YSI at site A was relocated to a slightly deeper location about 4 m from its original location. At Site C, the YSI was deployed with the Aquadopp in approximately 1 m of water. Aquadopp - The aquadopp was set to collect current velocity and direction (1 MHz instrument frequency) as well as wave height and direction (2 Hz sampling rate and 2400 samples) every 2 hours. Current data was set to average only 1 second of measurements. Wave data and current profile data were collected vertically in 0.3 m bins starting from a 0.2 m blanking distance above the transducers up to the air-water interface. It was mounted horizontally on a deployment platform with the transducers facing upward, approximately 24 cm above the seabed in about 1 m of water. RBR Solo - 30 minutes at 16 Hz for 8192 samples, which equates to approximately 8.5 minutes of measurement. The RBRs were deployed on the marsh top. Because the marsh top is not always inundated, there are long data gaps measured at each of the RBRs. The RBRs were deployed in a transect from the marsh scarp to the interior marsh with one RBR offset from the transect as a reference point RTK - Trimble R8 Real Time Kinematic Differential GPS (RTK-DGPS) system with a pole mounted receiver Sediment Tiles - 15 cm by 15 cm unpolished ceramic tiles, placed on the marsh surface; only a 10 cm by 10 cm area from each tile was sampled using a 3D printed 'cookie cutter' With the exception of the wave data, all uploaded data was averaged hourly.

Individual Files: