Annualmeeting:2017 CSDMS meeting-111
Sustainability and Operational Design of Sediment Delivering River Diversions
- Man Liang, The Water Institute of the Gulf Baton Rouge Louisiana, United States. email@example.com
- Ehab Meselhe, The Water Institute of the Gulf Baton Rouge Louisiana, United States. firstname.lastname@example.org
In order to guide the operational design of two planned diversions in the Lower Mississippi River, we apply Delft3D to simulate diversion discharge through time as a function of the characteristics of the receiving basin. In both cases the conveyance channel connecting the river to the basin is prevented from eroding.
We find that diversions in basins that offer many outlets for flow are more likely to maintain their discharge over a ten-year time horizon. We also find that diversion performance is not significantly affected by substrate erodibilities in the range of those found in the Mississippi River Delta, but that artificially increased bed strength would lead to decreases in performance. Our work also sheds light on the spatial pattern of erosion near a diversion. We find that very little erosion into the substrate occurs away from the immediate vicinity of the outfall channel, but that the evolution of the proximal scour is a critical control on the sustainability of the diversion. Ecological considerations suggest that operating diversions at low flow might be useful, but this practice increases the risk of back flow from the receiving basin.