1. The Flow of Freshwater

2. How is the Earth’s Water Distributed?

3. How does this freshwater flow across the surface of the earth?

4. RIVERS
Rivers? Streams? Creeks? They are all names for water flowing on the Earth's surface
Where does the water come from to fill these?

5. The Water Cycle
The continuous movement of water from the ocean to the atmosphere to the land and back to the ocean.

7. Model of river running from the mountains to the sea.

8. Parts of a River System

9. Continental divide of the United States
River systems are divided into regions called watersheds or drainage basins
This is the area of land that is drained by a water system.
River systems are separated from each other by areas of higher ground called a divide.

10. Drainage of river systems

11. Cross section of a River

12. Definitions
Tributary: a stream that flows into a lake or into a larger stream
Channel: the path that a stream follows
Bed: the bottom of the stream
Load: the materials carried by the stream
Bed load: the materials carried along the bottom of the stream
Suspended load: materials carried in suspension (floating in the water)
Dissolved load: materials carried in solution, they usually cannot be seen.

13. Bed flow and direction

14. How do these rivers form?
Erosion: the process by which soil and sediment are transported from one location to another.
It can be transported by wind, water, ice or gravity.

15. What is this and how did it form?

16. The Grand Canyon and it was all formed by EROSION !!

17. STREAM EROSION
As a stream forms it erodes soil and rock to make a channel.
When it first forms, it is usually narrow and steep. Over time, the stream transports more rock and soil downstream and makes the channel wider and deeper.
When streams become longer and wider they are called rivers.

18. Factors that influence a stream’s ability to erode
Gradient: measure of the change in elevation over a certain distance (how steep it is)
Discharge: amount of water that a stream or river carries in a given amount of time.
Load: the materials carried by the stream.

19. 3 stages of a River Youthful River Mature River Old River
Rejuvenated River

20. Characteristics of a Youthful River
Channel is eroded deeper rather than wider
Water flows quickly because it has a steep gradient
Has rapids and waterfalls
Have very few tributaries
HIGH erosive energy

21. Youthful River Yosemite National Park

22. Characteristics of a Mature River
Erodes channel wider rather than deeper
Does not have a steep gradient
Few rapids or waterfalls
Has many tributaries
Has more discharge than a youthful river
Has meanders

23. Meandering Stream
Mature rivers curve back and forth. The bends in the river are called meanders.

24. Mature River

25. Characteristics of an Old River
Low gradient and low erosive energy
Instead of widening and deepening its banks, the river deposits its soils in and along its channel
Have wide flat flood plains (valleys)
Has few tributaries

26. Old River

27. Rejuvenated River
A river whose gradient (steepness) has been raised by tectonic activity (movement of the crust of the earth).