Thinking Citizen Blog — the Mississippi — Upper, Middle, Lower
Thinking Citizen Blog — Wednesday is Climate Change, the Environment, and Sustainability Day
Today’s Topic: Great Rivers of the World X: the Mississippi — Upper, Middle, Lower
The river is 2230 miles long and drains all or part of 32 states accounting for 40% of the landmass of the continental US. This would make its watershed (sometimes called its “catchment”) the fourth largest in the world. Its history is rich from the Native American mound-building cultures, to the time of European explorers, steamboats, and the Civil War. And then, of course, there is the raft with Huck, Tom, and Jim. Today, a few notes on the three separate segments of the river. Experts — please chime in. Correct, elaborate, elucidate.
THE UPPER MISSISSIPPI: from Lake Itasca (Minnesota) to St. Louis (confluence with the Missouri River)
1. 43 dams — 14 north of Minneapolis; 29 from downtown Minneapolis to St. Louis.
2. “a multi-thread stream with many bars and islands.”
3. “From its confluence with the St. Croix River downstream to Dubuque, Iowa, the river is entrenched, with high bedrock bluffs lying on either side. The height of these bluffs decreases to the south of Dubuque, though they are still significant through Savana, Illinois.”
NB: “This topography contrasts strongly with the Lower Mississippi, which is a meandering river in a broad, flat area, only rarely flowing alongside a bluff (as at Vicksburg, Mississippi).
THE MIDDLE MISSISSIPPI: from St. Louis to Cairo (confluence with the Ohio)
1. The Ohio River, the largest tributary in terms of volume. originates in western Pennsylvania and is 981 miles long, flowing through six states. The Ohio’s principal tributary is the Tennessee (652 miles long).
2. The Missouri is actually longer than the Mississippi (2341 miles versus 2230). Unlike the Ohio, it drains a sparsely populated region.
3. The middle stretch of the Mississippi between the Missouri and the Ohio is short (190 miles) and general free flowing (no locks, dams, levees, dykes).
NB: The picture above is a photo of the confluence of the Ohio (right) and the Mississippi (left) at Cairo.
THE LOWER MISSISSIPPI: From Cairo to the Gulf fo Mexico
1. Major tributaries: White River, Arkansas River, Big Black River, and the Yazoo (meeting at Vicksburg).
2. “Deliberate water diversion at the Old River Control Structure in Louisiana allows the Atchafalaya in Louisiana to be a major distributary of the Mississippi River, with 30% of the combined flow of the Mississippi and Red Rivers flowing to the Gulf of Mexico by this route, rather than continuing down the Mississippi’s current channel past Baton Rouge and New Orleans on a longer route to the Gulf.”
3. No locks or dams. Constrained by levees (to prevent flooding) and dykes (to protect land that would naturally be underwater).
NB: Photo above is of the lower Mississippi near New Orleans.
Please share the coolest thing you learned in the last week related to climate change or the environment. Or the coolest, most important thing you learned in your life related to climate change that the rest of us may have missed. Your favorite chart or table perhaps…
This is your chance to make someone’s day. Or to cement in your own mind something that you might otherwise forget. Or to think more deeply than otherwise about something dear to your heart.