1. Objectives Describe how surface water can move weathered materials.
Section 9.1
Surface Water Movement
Objectives
Describe how surface water can move weathered materials.
Explain how a stream carries its load.
Describe how a floodplain develops.
Running water is an agent of erosion, carrying sediments in streams and rivers and depositing them downstream.

2. Section 9.1
1. Runoff

3. What determines the amount of runoff?
Section 9.1
What determines the amount of runoff?
1. Soil composition
Pore spaces:
The particle size that makes up a soil helps determine the pore space of the soil.
Porosity Activity
Large grain size Fine grain size Mixed grain size

4. If precipitation exceeds infiltration, the water will become runoff.
Section 9.1
What determines the amount of runoff?
2. Rate of precipitation
If precipitation exceeds infiltration, the water will become runoff.

6. Vegetation slows runoff
Section 9.1
What determines the amount of runoff?
3. Vegetation
Vegetation slows runoff

8. The steeper the slope, the faster the water flows.
Section 9.1
Surface Water Movement
Runoff Activity
4. Slope
Water from precipitation falling on slopes flows to areas of lower elevation.
The steeper the slope, the faster the water flows.

10. Section 9.1
Surface Water Movement
Stream Systems
Some surface water flows in thin sheets and eventually collects in small channels, which are the physical areas where streams flow.

11. Stream Systems Tributaries
Section 9.1
Surface Water Movement
Stream Systems
Tributaries
Rivers that flow into other streams are called tributaries.

13. Stream Systems Watersheds and divides
Section 9.1
Surface Water Movement
Stream Systems
Watersheds and divides
All of the land area whose water drains into a stream system is called the system’s watershed.
A divide is a high land area that separates one watershed from another.

14. The watershed of the Mississippi River
Section 9.1
Surface Water Movement
The watershed of the Mississippi River

15. Section 9.1
Surface Water Movement
Stream Load
The material that a stream carries is known as stream load. Stream load is carried in three ways.

16. Section 9.1
Surface Water Movement
1. Suspension
all particles are held up by the turbulence of a stream’s moving water.

17. Sketch

18. Section 9.1
Surface Water Movement
2. Bed load
sand, pebbles, and cobbles that can be rolled or pushed along the bed of the stream.

19. Sketch

20. Section 9.1
Stream Load Activity
Surface Water Movement
3. Solution
When water runs through or over rocks with soluble minerals, it dissolves small amounts of the minerals and carries them away in the solution.

21. Sketch

22. Stream Carrying Capacity
Section 9.1
Surface Water Movement
Stream Carrying Capacity
The ability of a stream to transport material, referred to as its carrying capacity,
Depends on both the velocity and the amount of water moving in the stream.

23. Section 9.1
Surface Water Movement
Floods
A flood occurs when water spills over the sides of a stream’s banks onto the adjacent land.

24. Flood plains Surface Water Movement
Section 9.1
Surface Water Movement
Flood plains
The area that extends out from a stream’s bank and is covered by excess water during times of flooding is known as the stream’s floodplain

25. Section 9.2
Stream Development
Objectives
Describe some of the physical features of stream development.
Describe the relationship between meanders and stream flow.
Explain the process of rejuvenation in the stream development.
Streams erode paths through sediment and rock, forming V-shaped stream valleys.

26. Section 9.2
Stream Development
Supply of Water
The region where water first accumulates to supply a stream is called the headwaters.
Stream channels

27. Section 9.2
Stream Development
Stream channels
Moving water carves a narrow pathway into the sediment or rock called the stream channel.

28. Formation of Stream Valleys
Section 9.2
Stream Development
Formation of Stream Valleys
A bend or curve in a stream channel caused by moving water is called a meander.
Meanders

29. Meanders - Movie Clip Outside of meander
Section 9.2
Stream Development
Meanders - Movie Clip
Outside of meander
Water moving along the outside of a meander curve experiences the speed with the meander and erodes the side of the streambed.
Inside of meander
Along the inside of a meander, the water moves more slowly and deposition is dominant.

31. Sketch

32. Deposition of Sediment
Section 9.2
Stream Development
Deposition of Sediment
When streams lose velocity, they lose some of the energy needed to transport sediment, and deposition of sediment occurs.

33. composed mostly of sand and gravel.
Section 9.2
Stream Development
1. Alluvial fans
fan-shaped, sloping depositional features that form when water flows down steep slopes onto flat plains.
composed mostly of sand and gravel.

34. consist of layers of silt and clay particles.
Section 9.2
Stream Development
2. Deltas
triangular deposit that forms where a stream enters a large body of water
consist of layers of silt and clay particles.
Nile delta

36. Complete the diagram on page 43 Complete the front side of the worksheet using your notes and textbook “Features of a Meandering Stream”