What accounts for the shape of the Mississipi River Delta?

[twhitt]

Browsing google maps for a while, I looked up the mouths of some of the largest rivers in the world. I checked the Mississippi, Amazon, Nile, and Yangtze. Of these, the Mississippi seems unique in that it branches heavily and appears to be actively depositing sediment to form above-sea-level land in narrow chutes. The Nile also seems to branch, but it’s mouth looks quite different from the Mississippi, being more broad and flat. The Amazon and the Yangtze don’t seem to branch at all, but empty into the ocean as a gradually broadening mouth. What’s different about these rivers that causes them to have such different formations at their respective mouths?

[Yllaria]

Perhaps the Mississippi has been more engineered than other rivers. A little light reading. It doesn’t answer your question directly, but it speaks to how much the Army Corps of Engineers has worked on the river.

[twhitt]

The newest delta at the mouth of the Mississippi is five hundred years old. I’m sure that engineering could be affecting its future shape, but what made it so different in the first place?

[Squink]

2 Types of deltas

* 2.1 River-dominated deltas
* 2.2 Wave-dominated deltas
* 2.3 Tide-dominated deltas
* 2.4 Gilbert deltas
* 2.5 Estuaries
* 2.6 Inland deltas

River delta

River dominated deltas, such as the Mississippi delta, usually take on a multi-lobed shape that results from repeated sequences of channel occupation, offshore deposition, and channel avulsion. (See delta switching.)
…
In wave dominated deltas, wave erosion controls the shape of the delta, although deposition still outweighs the amount of erosion and the delta is able to advance into the sea. Deltas of this form, such as the Nile delta, tend to have a characteristic Greek-capital-delta shape