The document discusses deserts and winds. It describes where deserts are located globally and what factors cause deserts, including air pressure, wind patterns, and the relationship between rainfall and evaporation. Deserts form at low latitudes near the Tropics of Cancer and Capricorn as well as in middle latitudes in "rain shadows." The document also discusses basin and range topography as well as how wind erosion shapes desert landscapes through the formation of different types of sand dunes, desert pavement, and graded beds.

1. Deserts & Winds

2. “We don’t survive the desert,
we live here”
- Pima Indian

3. Deserts & winds
1) Deserts: where & why
Earth’s dry regions: 30% of all land
2 climate types of dry regions:
q desert (arid)
q steppe (semi-arid, surrounds deserts)

4. Deserts & winds
1) Deserts: where & why
What causes deserts?
Important factors:
Global distribution of
q air pressure
q wind
Relationship between
q rainfall
q evaporation
www.weatherchannel.com

5. Deserts & winds 1) Deserts: where & why

6. Deserts & winds
1) Deserts: where & why
Low-latitude deserts
(recall: “latitude” = east-west line on the globe)
x Tropic of Cancer
x Tropic of Capricorn
In contrast….
x Equator:
x hot air
x rises to 15-20 km
x low pressure belt

7. Deserts & winds 1) Deserts: where & why

8. Deserts & winds 1) Deserts: where & why

9. Deserts & winds 1) Deserts: where & why

10. Deserts & winds
1) Deserts: where & why
Middle-latitude deserts
x exist in rain shadows.

11. Deserts & winds
2) Basin and range
Basin and range
x mountainous desert landscape

12. Deserts & winds
2) Basin and range
Basin and range
x mountainous desert landscape

13. Deserts & winds 3) Wind erosion/ deposits
Wind erosion: Important in arid environments
Example: Types of sand dunes:
Sand dune shape depends on:
Flat
or hilly?
How much sand?
Winds steady or intermittent?
Wind direction constant?
Vegetation present?

15. Deserts & winds 3) Wind erosion/ deposits
Sand dune formation

16. Deserts & winds 3) Wind erosion/ deposits
Desert pavement

17. Deserts & winds 3) Wind erosion/ deposits

19. Deserts & winds 3) Wind erosion/ deposits
Graded beds