Mathematical Study of the Impact on Salinity Intrusion of Deepening the Lower Mississippi River Navigation Channel

摘要

The US Army Engineer District, New Orleans has been evaluating the feasibility of deeper draft access to the ports of New Orleans and Baton Rouge, Louisiana. One of the factors being considered in the evaluation is the impact of the deeper channel on salinity intrusion in the Lower Mississippi River. The importance of such an evaluation is because the city of New Orleans relies primarily upon the Mississippi River for its supply of fresh water. A major reason for conducting the numerical modeling study was not only to evaluate the impact of a deeper channel on salinity intrusion using historical riverflows but also to use the numerical model to determine the impact on the wedge intrusion of increasing the height of natural river crossings, i.e., creating a sill in the river. To address the question of the stability of such a sill composed of natural sediment, the HEC-6 computer program Scour and Deposition in Rivers and Reservoirs, HEC (1977), was applied.