1. Do Now!!!
Begin vocab on notes packet

2. Don’t copy the words in this color

3. 4.1 Surface Water Objectives: Identify the causes of runoff.
Compare rill, gully, sheet, and stream erosion.
Identify three different stages of stream development.
Explain how alluvial fans and deltas form.

4. Module G, Chapter 4:
Water Erosion
and Deposition

6. Runoff Runoff is water that does not soak into the or . ground
It flows into streams, lakes or oceans.
ground
evaporate

7. Factors that Effect Runoff:
amount of rain
time
vegetation
slope

9. Gravity Earth energy erodes Gravity pulls water toward the .
As the water moves, it builds
and the surrounding rock and soil.
energy
erodes

10. After heavy rains, form and Rill Erosion ________________
________ the land.
small streams
erode

11. deeper and wider forming .
Gully Erosion
Over time, become
deeper and wider forming
rill channels
gullies

12. water flows into lower elevations carrying sediments with it.
Sheet Erosion
Over a , rain
water flows into lower elevations
carrying sediments with it.
flat area

13. Stream Erosion
When a stream forms, the water continues to pick up sediments from the and of the channel.
bottom
sides

14. River System Development
gullies
Water from __________, __________ and ______________ located upstream flow into larger streams which flow into rivers.
rills
small streams

15. Drainage Basins land area A drainage basin is a from
which a or gets its
water. The largest drainage basin in the
USA is the
stream
river
Mississippi River

17. Stages of Stream Development!!!1.
Young 2.
Mature
Old 3.

18. Young Streams quickly flow ______________ have ________ sides
whitewater rapids
water falls
have a high level of
___________
erode the ____________
steep
energy
bottom

19. Mature Stream
Mature streams flow _____________ and most of the larger rocks have eroded away.
It also erodes away at the ____________ rather than the bottom. This causes it to develop curves also known as ___________.
less swiftly
sides
meanders

20. Old Stream
Old streams flow ___________. They are __________, ___________ and flow into flood ___________ .
slowly
broad
flat
plains

21. Deposition by Surface Water
alluvial fan
An ___ is made by sediments being dropped as a river flows on a level surface and slows down.

23. Named after the Greek letter Delta = ∆
Deltas
Named after the Greek letter Delta = ∆
Sediment that is deposited as water empties into an _________ or __________ forms a triangular, or fan-shaped deposit called a __________.
ocean
lake
delta
Nile Delta

25. Check for Understanding
1. Explain how the slope of an area affects runoff.
2. Compare and contrast rill and gully erosion.
3. Describe the three stages of stream development.
4. Compare and contrast the formation of deltas and alluvial fans.