1. Moving water shapes land
5-2 Notes
Moving water shapes land

2. Streams Shape Earth’s Surface
What do you notice these three streams all have in common?

3. Streams Shape Earth’s Surface
You probably noticed (among other things):
The land is higher than the water
The land is sloping down to the water
The water is moving downhill

4. Streams Shape Earth’s Surface
Running water is the major agent of erosion shaping the landscape of Earth.

5. Streams Shape Earth’s Surface
Running water shapes landforms by moving sediment in the processes of erosion and deposition.

6. Streams Shape Earth’s Surface
A stream is a body of water-large or small-that flows down a slope along a channel.

7. Drainage Basins and Divides
Streams flow into one another to form complex systems.
Small streams flow into larger ones.

8. Drainage Basins and Divides
The area of land in which water drains into a stream system is called a drainage basin.

9. Drainage Basins and Divides
Most drainage basins eventually drain into a lake or ocean.
Example: the Mississippi River drainage basin empties into the Gulf of Mexico.

10. Drainage Basins and Divides
Drainage basins can be a few kilometers wide or can take up a large portion of a continent.

11. Drainage Basins and Divides
Drainage basins are separated by ridges called divides-a ridge from which water drains to one side or the other.

12. Valleys and Floodplains
As streams flow and carry sediment, they form valleys.

13. Valleys and Floodplains
In high mountains, streams often cut V- shaped valleys that are narrow and steep.

14. Valleys and Floodplains
In lower areas, streams may form wide valleys that include floodplains-an area of land on either side of a stream that is underwater when the stream floods.

15. Valleys and Floodplains
When a stream floods, it deposits the sediment it carries onto the floodplain.
This makes floodplains very fertile-able to support a lot of plant growth.

16. Valleys and Floodplains
The floodplains of the Mississippi river are some of the best places for growing crops in the U.S.

17. Stream Channels
As a stream flows through a valley, its channel may run straight in some parts and curve in other parts.

18. Stream Channels
Curves and bends that form a twisting, looping pattern are called meanders.

19. Stream Channels
Over many years, meanders can change position and get cut off from the rest of the stream.
A cut-off meander forms a crescent shaped lake called an oxbow lake.

20. Alluvial Fans and Deltas
Alluvial fan- a fan- shaped deposit of sediment at the base of a mountain created by a stream.

21. Alluvial Fans and Deltas
Alluvial fans are formed when a stream leaves a steep valley and enters a flatter plain.

22. Alluvial Fans and Deltas
Delta- an area of land formed by the buildup of sediment at the end of a river.
Over time, a delta builds up into a fan-shaped plain.

23. Alluvial Fans and Deltas
Over a very long time, a river can build up a huge delta that reaches out to sea.

24. Water Moving Underground Forms Caverns
Not all rainwater runs off the land and flows into streams.
Some of it evaporates, some is absorbed by plants, and some soaks into the ground to become groundwater.

25. Water Moving Underground Forms Caverns
At a certain depth below the surface, the spaces in soil and rock become completely filled with water.
The top of this region is called the water table.

26. Water Moving Underground Forms Caverns
Water below the water table is called groundwater.

27. Water Moving Underground Forms Caverns
As groundwater flows through rock and soil, it causes erosion.
Groundwater erosion causes certain rocks (like limestone) to dissolve.

28. Water Moving Underground Forms Caverns
Over time, this process produces open spaces called caves.
Very large caves are called caverns.

29. Kartchner Caverns, Arizona

30. Carlsbad Caverns, New Mexico

31. Onandaga Cave, Missouri

32. Waitomo Glowworm Cave, New Zealand

33. Cave of Crystals, Mexico

34. Water Moving Underground Forms Caverns
Sinkhole- a basin formed when the roof of a cave suddenly falls in

35. Devil’s Toilet Bowl, Florida

36. Devil’s Sinkhole, Texas

37. Guatemala City Sinkhole, Guatemala

38. Heavenly Pit Sinkhole, China

39. Great Blue Hole, Belize

40. Review
1. A sinkhole is formed by the collapse of
A. an alluvial fan
B. a cavern
C. a moraine
D. a kettle lake

41. 2. Rivers transport sediment to A. Drainage basins B. Oceans and lakes
Review
2. Rivers transport sediment to
A. Drainage basins
B. Oceans and lakes
C. The water table
D. Moraines

42. Review
3. Drainage basins are separated by a
A. moraine
B. divide
C. tributary
D. barrier island

43. Review
4. In high mountains, a valley carved by a stream has the shape of a
A. U
B. Crescent
C. Plate
D. V

44. Review 5. An oxbow lake is formed by the cutting off of a A. meander
B. drainage basin
C. sinkhole
D. glacier