Semester of Graduation
Fall 2024
Degree
Master of Science (MS)
Department
Civil and Environmental Engineering
Document Type
Thesis
Abstract
The fate of soil organic carbon loss from eroding coastal wetlands is of great importance, given its potential impact on atmospheric CO2 concentration. A large fraction of this soil organic carbon upon coastal erosion is released as dissolved organic and inorganic carbon (DOC and DIC) to adjacent water bodies.
In this study, we investigate the seasonal distribution and transport of DOC and DIC in Barataria basin in Louisiana, USA, bordering northern Gulf of Mexico. This region is currently undergoing one of the highest land-loss in the USA. Seasonal measurements of DOC, DIC and colored dissolved organic matter (CDOM) were carried out during Winter, Spring, Summer, and Fall of 2020-2021. The average DOC in the Barataria basin varied between 7.78 mg/l in winter, 10.41 mg/l in spring, 2582.47 uM in fall, and 1553.26 uM in winter. DOC and DIC concentrations were highest in the northern part of the bay compared to the southern open ocean side. Concurrently, humification index decreased with salinity gradient and a statistical correlation analysis suggests a strong influence of terrigenous organic matter input in the northern part of the bay.
Furthermore, the seamless creek-to-ocean SCHISM 3D model validated by data from the east coast and the coast of Gulf of Mexico was implemented in this study to compute the mean velocity and discharge rate in the Barataria basin. This allows us to combine the DOC field data with the modeled discharge data to assess the seasonal DOC transport. The estimate suggests that the highest DOC was exported in spring at 201.6 tons per day which is significant when compared to Mississippi River which brings on average 12.4 million tons per day. This DOC export from estuaries should be incorporated in ocean carbon budget to better understand its impact on atmospheric CO2.
Date
8-26-2024
Recommended Citation
Mahmood, Mukseet, "Sources and Transport of Dissolved Organic Carbon in Barataria Basin, Louisiana" (2024). LSU Master's Theses. 6032.
https://repository.lsu.edu/gradschool_theses/6032
Committee Chair
Willson, Clinton S.