Hot deserts

Question 1

Describe the temperature of a hot desert

Answer 1

High daily temperatures up to 50°C
Low night time temperatures less than 20°C

Huge temperature range of 30°C

Question 2

Describe the rainfall of a hot desert

Question 3

Describe the climate of a hot desert

Answer 3

Hot subtropical latitudes

Question 4

Why are there high daily temperatures (3)

Answer 4

There are no clouds to protect the land from the powerful sun

Sand/ rock can heat up quickly

No water to moderate heat

Question 5

Why are there low nightly temperatures

Answer 5

No clouds to keep in the heat

Question 6

Where will there be a wider variety of vegetation in the desert

Answer 6

Where it is wettest

Question 7

Example of a place with a hot desert climate

What is the climate like there

Answer 7

Timbuktu, Mali

Total annual rainfall - 218mm
Seasonality - mild seasons, slightly wetter/ hotter season due to latitude
Temperature - 23°C to 35°C
Temperature range - 12°C

Question 8

What is a Hadley cell

Answer 8

The circulation of air around the equatorial region

Question 9

How does a Hadley cell form

Answer 9

Hot moist air from the tropics rise, cool and condense to form cloud.

The turn of the earth causes the air to deflect

The air starts to cool and sink to high pressure at 40° N/S

This air is the pushed back into the tropics where there is low pressure left by the risen air

Question 10

Why is it dry at the Sahara

Answer 10

Has sinking air which creates high pressure zones

Question 11

How has the fennec fox adapted to the desert (6)

Answer 11

Small to lose heat easily

Large ears to radiate heat

Thick feet to protect from burning sand, big feet so they don’t sink into the sand

Thick fur to insulate during the night

Large eyes to see in the dark as it is cooler at night, more food, nocturnal

Sandy colour to be camouflage and to offer protection from the sun

Question 12

How has vegetation adapted to arid conditions (8)

Answer 12

Spreads leaves to be broad to maximise photosynthesis

Putting leaves tall to prevent grazing

Ability to pump an alkaloid into leaves when eaten

Small leaves limit transpiration (small SA)

Spiney leaves to prevent animals from eating

Pyrophytic/ fire resistant from lightning

Shallow roots as the ground is too hard and to suck up moisture on the surface

Thrives independently so it can have all the water to itself

Question 13

What is desertification

Answer 13

The turning of land into desert, the spreading of deserts into areas of previously productive land

Question 14

Reasons for desertification

Answer 14

Climate change
Too many animals
Population growth

Question 15

How does climate change cause deforestation

Answer 15

Less rainfall or increases temperatures cause rivers and water holes to dry up so vegetation dies.
Decrease of protective vegetation cover so the soil is exposed to wind, rain and erosion so the desert spreads

Question 16

How does too many animals cause desertification

Answer 16

Too many animals cause over grazing which causes the vegetation to not be able to establish itself
Decrease of protective vegetation cover so the soil is exposed to wind, rain and erosion so the desert spreads

Question 17

How does population growth cause desertification

Answer 17

More land needs to be used for crops as there is a higher demand for food so over cultivation reduces soil fertility so vegetation is removed

Or it increases the demand for fuel wood for energy which increase deforestation so vegetation is removed

Decrease of protective vegetation cover so the soil is exposed to wind, rain and erosion so the dessert spreads