Water Resources Research Act Program

Details for Project ID 2020LA035B

Mid-Barataria Sediment Diversion Efficiency Assessment through Computational Fluid Dynamics Modelling

Institute: Louisiana
Year Established: 2020 Start Date: 2020-03-01 End Date: 2021-02-28
Total Federal Funds: $15,000 Total Non-Federal Funds: $30,001

Principal Investigators: Celalettin Ozdemir

Abstract: Louisiana is facing a potentially catastrophic crisis due to the alarmingly high rate of land loss. Land loss results from a compound effect of coastal erosion due to sea level rise and rapid changes in climatic patterns, low sediment delivery from the upper Mississippi River, subsidence, and land cover and land-use change in the lower Mississippi River basin and its distributaries. Although these stressors are convoluted, their fast-pacing effect on land loss calls for utilizing the existing scientific knowledge and technical expertise. Recognizing the urgency of the problem, in the State of Louisiana’s 2017 Coastal Master Plan, several projects, including sediment diversion, marsh creation, barrier island restoration, etc., have been prioritized. Constructing sediment diversions aims at building new land in the form of down-scaled versions of natural deltaic lobes by using the stream power of the Mississippi River to deliver the sediment. However, building stable strata for the new land requires more sand than that exist in the Mississippi River. Therefore, the sand content of the diverted water should be higher than the Mississippi River’s sand content, if not equal. While maximizing the efficiency of the sediment diversions, the navigability of the Mississippi River should be maintained, and possible shoaling due to reduction in the stream caused by the water withdrawal must be avoided. The given constraints suggest that the operational strategy of the sediment diversions must be carefully designed. The proposed work aims at developing an operational strategy for the Mid-Barataria sediment diversion by conducting highly resolved computational fluid dynamics (CFD) simulations in the vicinity of the Mid-Barataria sediment diversion rather than conducting simulations along the lower Mississippi River reach. The proposed simulations will allow for better resolution of the essential flow features that potentially impact the sediment intake by the diversion. In the proposed simulations, suspended sediments will be traced via one-way coupled Lagrangian particles, and bed shear stress over the Mississippi River near the diversion will be calculated to determine shoaling-prone areas. The results will be analyzed to determine the optimal operational strategy to harness the maximum amount of suspended sand while maintaining the navigability of the Mississippi River.