Introductory Activity : Read this excerpt to the students:
"The Mississippi is well worth reading about. It is not a commonplace river, but on the contrary is in all ways remarkable. Considering the Missouri its main branch, it is the longest river in the world -- four thousand three hundred miles. It seems safe to say that it is also the crookedest river in the world, since in one part of its journey it uses up one thousand three hundred miles to cover the same ground that the crow would fly over in six hundred and seventy-five. It discharges three times as much water as the St. Lawrence, twenty-five times as much as the Rhine, and three hundred and thirty-eight times as much as the Thames. No other river has so vast a drainage-basin: it draws its water supply ... from Delaware, on the Atlantic seaboard, and from all the country between that and Idaho on the Pacific slope -- a spread of forty-five degrees of longitude. The Mississippi receives and carries to the Gulf water from fifty-four subordinate rivers that are navigable by steamboats, and from some hundreds that are navigable by flats and keels. The area of its drainage-basin is as great as the combined areas of England, Wales, Scotland, Ireland, France, Spain, Portugal, Germany, Austria, Italy, and Turkey; and almost all this wide region is fertile; the Mississippi valley, proper, is exceptionally so."
-- from Life on the Mississippi, written by Mark Twain in 1863
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Body : Tell students that they will be learning about energy and how the amount of energy a river has determines how it will change the landscape.
? The Mississippi river is the largest in the united states.
? Moving water carries particles and sediments along with it.
? The more energy a river has, the more it can carry. This is its load.
o Have a volunteer come to the front of the room. Give them a large object and have them jump up and down with it or move around the room. Next give them a lighter object and repeat the movement.
? Ask: Which part was harder to do? (Move with the heavier object.)
? Ask: Which took more energy to do? (Move with the heavier object.)
? The more energy a river has, the more it can carry.
? Ask: What can slow a river down?
o The smoother the channel, the faster it can go.
o Have two volunteers come to the front of the room.
o Have them race from one point to another. Have one student run straight to the finish and have the other run over an obstacle course.
? Ask: Which student was faster?
? Ask: What would have made the slower student faster?
? Ask: What happens to the speed of a river when it floods and runs over its banks?
o It slows down because the path is no longer smooth.
? Ask: What happens to the sediments carried by the river when it floods?
o The river looses energy when it moves over rough ground and it is no longer able to carry its load.
? This is how a flood plain forms. The sediments deposited here are very rich and good for farming.
? Ask: What happens to sediments in a river when it hits the large ocean?
o They are deposited because the speed of the river decreases.
o This area, where the river meets the ocean is called a delta.
? Have students look at their maps of the Mississippi and identify flood planes and the delta.
? Ask: How has Mississippi (the state) and Louisiana been in the news lately?
? During hurricane Katrina the structures that people have built to keep out the water failed.
? In the 1930?s the Army Corps of Engineers built a system of dams and locks to keep the Mississippi river on course.
? Discuss with the students why it would be important for the Mississippi to stay on the course it has taken.
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