Why is the lower Mississippi River described as a meandering alluvial river?

The lower Mississippi River is described as a meandering alluvial river because it flows across a vast floodplain composed of alluvial materials—sediments deposited by the river itself over time.12

In this environment, the river channel is not fixed; instead, it loops and curls extravagantly across the landscape. Because these alluvial deposits offer little resistance to erosion, the river is able to freely adjust its shape, shifting its course over time. This process creates distinctive features such as meander scars, cutoffs, and oxbow lakes.312

Geographically, this section of the river occupies a large trough that was historically carved by glacial meltwaters and subsequently filled with deep layers of sediment. While the river’s natural tendency is to meander as a way to minimize flow resistance and work, its path is now largely constrained by human-made levees and other control structures.143