Hot deserts

Question 1

Location of Hot deserts

Answer 1

30N or 30S of the equator

Just by the hadley cell

Question 2

What is the definition of a desert

Answer 2

A desert is an area that receives less than 250mm of rainfall per year.

Question 3

Reasons for climate of hot desert

Answer 3

-Air is sinking near the tropics

-Leading to areas of high pressure

-This results in fewer clouds

-Therefore temperature is hot during day and cold at night due to lack of cloud cover

Question 4

How hot are deserts during the day and night

Answer 4

50C in the day and below 0C at night

Question 5

Relationship between plants and soil

Answer 5

-Vegetation provides cover for soil and food for animals

-Soil provides the structure for roots to take hold and grow

Question 6

How has a saguaro cactus adapted to conditions

Answer 6

-They can store up to 9 tonnes of water

-They grow really slowly to preserve energy levels

-Can lose 82% of water before dying of dehydration

Question 7

How have roots adapted to conditions

Answer 7

-To make most of sudden rainfall some roots are very shallow and cover a large area

-Some roots go deep in search of water (25m)

Question 8

Case study for Hot deserts

Answer 8

The Western desert

Question 9

Location of western desert

Answer 9

-Made up of 3 smaller deserts: Mojave, Sonora and Chihuahuan.

In Arizona, New Mexico and Nevada, USA

Question 10

Opportunities in the western desert

Answer 10

Energy generation, Farming, Tourism, Mineral extraction

Question 11

Reasons for tourism in WD

Answer 11

-Many people want to visit the national parks and wilderness areas, to experience a new part of the world

Question 12

Challenges of Tourism in WD

Answer 12

-Lack of access as there is a lack of infrastructure

-Extreme heat and lack of water affect tourists and their accessibility to Western Desert

Question 13

Reasons for farming in WD

Answer 13

-High temp and sunlight is favourable for irrigation

-Xeriscaping , using drought resistant plants to store water

Question 14

Challenges of Farming in western desert

Answer 14

-Water droughts occur a lot in desert areas, no rainfall results in dead crops and plants.

Question 15

Reasons for Mineral extraction/Energy generation in WD

Answer 15

-Western desert is rich in minerals - copper mining happening for years

-Lots of space and lots of sunlight for solar energy

Question 16

Challenges of Mineral Extraction/Energy generation in WD

Answer 16

-Lack of water discouraging large scale mining

Question 17

Why is temperature a challenge

Answer 17

-Extreme temperatures over 50C lead to high rates of evaporation and water shortages

Question 18

How many people depend on water from Colorado river

Answer 18

30 million people

Question 19

How to overcome the extreme temperatures

Answer 19

-Implement flat roofs in houses to collect rainfall

Question 20

Give an example of lack of water being a challenge

Answer 20

-Nevada’s water deficit - lack of freshwater from Colorado river

Question 21

How to overcome lack of water supply

Answer 21

-Xeriscaping, gardens using drought resistant plants

-New developments in Las Vegas turning 50% of grass in gardens to cacti to store more water

Question 22

Give an example of inaccessibility being a challenge to the WD

Answer 22

-There is a lack of roads in Western desert due to low population desert

Question 23

How to overcome challenge of inaccessibility

Answer 23

-Las Vegas has 4 airports with 38.8 million tourist arrivals

-Southwest airline does 118 routes to Las Vegas increasing tourism

Question 24

Why is long term water security needed

Answer 24

-Increasing population growth and demand for water threatened by climate change

Question 25

How to ensure there is long term water security

Answer 25

-Storing water in reservoirs

-Large bodies of water such as Lake Mead reduce evaporation

Question 26

What is desertification

Answer 26

The process of land becoming drier and degrading in quality due to both human activities and natural processes

Question 27

Why is vegetation so important to soils

Answer 27

Vegetation provides shade for soils preventing it from too much exposure to the sun

-It also provides interception for rainfall making the impact on soil softer so the nutrients aren’t washed away

Question 28

Example of an area where desertification is occurring

Answer 28

The Sahel desert

Question 29

How is the Sahel solving desertification

Answer 29

The great green wall- 15km long band of trees and shrubs across the southern border of the Sahel

Question 30

Info of the great green wall -

Answer 30

-Spans through 11 countries in Africa

-The project is seen as a way of restoring land back to productivity.

Question 31

Strategies to reduce risks of desertification

Answer 31

• Afforestation

-Soil and water management

-Appropriate technology

Question 32

How does afforestation reduce desertification

Answer 32

-Prevents the ground drying out therefore soil erosion is prevented meaning vegetation can be planted

Question 33

How does soil and water management reduce desertification

Answer 33

-As it is cheap meaning locals can do this, stone walls trap soil so it isn’t eroded

-Soil erosion is prevented

-Less water is lost through surface run off

Question 34

How does using appropriate technology reduce risk of desertification

Answer 34

-Reduces need to cut down trees for firewood as there’s fuel efficient stoves

-There is more vegetation and reduced deforestation.

However this can be really expensive