1. Please take out your IAN!
Glue in the half sheet
of paper in the blue tub.
Chapter 11
The Flow of Fresh Water

2. Chap 11, Sec 1 (The Active River)
Objectives:
Describe how moving water shapes the surface of the Earth by the process of erosion.
Explain three factors that affect the rate of stream erosion.
Describe a watershed.
Describe how a stream or river erodes and deposits sediment simultaneously (at the same time).

3. Tech Terms:
tributary – a stream that flows into a lake or into a larger stream.
watershed (aka drainage basin) – the region that collects runoff water that becomes part of a river or a lake.

4. divide – (aka mountains)an area of higher ground that separates neighboring watersheds (ex Continental Divide).
The Continental Divide runs through the Rocky Mountains. It separates the watersheds that flow into the Atlantic Ocean and the Gulf of Mexico from those that flow into the Pacific Ocean.

5. Describe the difference between a watershed and a divide.
A divide is the boundary that separates drainage areas. A watershed

6. 3Factors of Stream Erosion:
4.Gradient-
5. discharge – the amount of water that a stream or river carries in a given amount of time
6. load- (3 types)
A stream’s ability to erode is influenced by these three factors!

8. Rivers and streams deposit sediment where the speed of the water current decreases. Figure 1 shows this type of deposition.
Placer Deposits
Heavy minerals are sometimes deposited at places in a river where the current slows down. This kind of sediment is called a placer deposit (PLAS uhr dee PAHZ it). Some placer deposits contain gold. During the California gold rush, which began in 1849, many miners panned for gold in the placer deposits of rivers

9. Tech Terms:
7. delta – a fan shaped depositional feature, formed when a load filled stream/river slows, as it enters a larger body of water.
As sediment is dropped at the mouth of the Nile River, in Egypt, a delta forms.

10. 8. alluvial fan – a fan shaped depositional feature, formed when a fast moving mountain stream flows onto a flat plain.

11. 9. flood plain – the area along a river that contains rich, fertile soil due to periodic overflow from a stream/river.
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