LIVING WORLD- hot deserts

Question 1

case study:

Answer 1

• Western desert USA

Question 2

what is mineral extraction?

Answer 2

• the removal of solid mineral resources from the earth

Question 3

what are hot deserts?

Answer 3

• parts of the world that have high average temperatures and very low precipitation
• an area receiving less that 250mm of rainfall resulting in extreme aridity

Question 4

what is desertification?

Answer 4

• the process of which land becomes drier and degraded, as a result of climate change, human activities or both

Question 5

what is overgrazing?

Answer 5

• the grazing of too many livestock for too long on the land, so it is unable to recover its vegetation

Question 6

what is over- cultivation?

Answer 6

• exhausting the soil by over-cropping the land

Question 7

what is appropriate technology?

Answer 7

• technology suited to the needs of local people that combines cheap materials and is environmentally friendly

Question 8

what is soil erosion?

Answer 8

• the removal of topsoil faster than it can be replaced, due to natural (water and wind), animal and human activity
• most fertile soil

Question 9

what is aridity?

Answer 9

• the state or quality of being extremely dry

Question 10

what are xerophytes?

Answer 10

• plants that can survive extremely dry conditions

Question 11

what is irrigation?

Answer 11

• the process of applying controlled amounts of water to the ground

Question 12

location of deserts:

Answer 12

• found between 15 and 35 degrees north and south of the equator

Question 13

how are desserts formed?

Answer 13

• in the Hadley cell
• most insolation at the equator
• heats the ground
• hot air rises and then cools and condenses at the equator so it rains
• cold air sinks above deserts and condenses heat in rainforests

Question 14

explain the location of hot deserts:

Answer 14

• air is sinking near the tropics
• leading to areas of high pressure
• resulting in no clouds
• temperature is therefore high during the day and colder at night

Question 15

what is soil like in a hot desert?

Answer 15

• dry and not very fertile
• due to a lack of rainfall and sparse vegetation
• little decomposing matter to enrich the soil
• the nutrients that are present decay rapidly due to high temps
• only few plants can survive- drought resistant cacti

Question 16

how can humans negatively impact interdependence?

Answer 16

• flocks of animals eat plants
• less plants mean less food for primary consumers
• less plants means soil will erode away, no protection from rainfall/wind means that there will be lots of evaporation from water
• less soil means plants cannot grow
• meaning no food or animals so they have to move to a new plot of land
• process repeats

Question 17

leave adaptations in hot deserts:

Answer 17

• desert yellow daisy
• small, linear, hairy leaves
• adapt to dry conditions and high temps

Question 18

root adaptations in hot deserts:

Answer 18

• prickly pear cactus
• some have shallow roots that spread over a large area
• some have deep roots (up to 25m)
• adapt to dry conditions, high temps and competition for nutrients

Question 19

how does the Saguaro cactus adapt to hot deserts?

Answer 19

• grows very slowly to conserve energy
• can store up to 9 tonnes of water
• body is made of vertical pleats that expand to allow greater storage
• can lose 82% of its water before dying of dehydration

Question 20

how is a camel adapted to hot deserts?

Answer 20

• can go a week or more without water
• can last several months without food
• can drink 32 gallons of water in one drinking session
• store fat in their hump- can be metabolised for energy
• body temperature fluctuates- allows camels to conserve water
• feet are wide so they can walk on sand without sinking in
• thick lips- can eat prickly plants

Question 21

how is the Peringney Adder adapted to hot desert conditions?

Answer 21

• move sideways- less than 50% of body in contact with hot sand

Question 22

what states does the Western Desert cover?

Answer 22

• Texas, Utah, New Mexico, California, Arizona

Question 23

energy opportunity in the Western Desert:

Answer 23

• Sonoran Solar project in Arizona which will supply energy to up to 100,000 homes
• 360 workers needed to help build it
• Hoover dam employed 5000 people

Question 24

tourism opportunity in the Western Desert:

Answer 24

• Lake Mead, Lake Powell- waterspouts
• Las Vegas attracts 37 million tourists a year

Question 25

challenges of tourism in the Western Desert:

Answer 25

- disrupts habitats of animals in Lake Powell+Mead - Grand Canyon can become eroded - More CO2 emissions as the desert is so far away

Question 26

why does farming happen in the Western Desert?

Answer 26

- happens due to high temperatures and sunlight - aquifers- large stores of water beneath hot desert regions

Question 27

examples of farming in the Western Desert:

Answer 27

- aquifer based farming in California's Coachella valley, produces lush crops of vegetables lemons, peppers, grapes (and in turn a wine industry)

Question 28

issues with farming in the Western Desert:

Answer 28

- for irrigation water has to be available- Las Vegas is running out of water

Question 29

why does mineral extraction or energy generation happen in the Western Desert?

Answer 29

- strong insolation provides for brilliant solar power farms - Western Desert is rich in minerals- copper, uranium, lead, zinc and coal

Question 30

what is mined in the Sonoran desert?

Answer 30

copper

Question 31

What is the dam called in Lake Mead?

Answer 31

- Hoover Dam

Question 32

challenges with mineral extraction/ energy generation:

Answer 32

- mineral extraction- conflicts with other land uses such as farming - environmental concerns with drilling

Question 33

how many motorways are there in the Western Desert?

Answer 33

- 2 - route 70 through Utah - Route 66 which connects Chicago with California (through the Western Desert) - very INACCESSIBLE

Question 34

challenges with water supply in the Western Desert:

Answer 34

- water is evaporating - can't get water from the Colorado River (2300km long) - have to store water underground

Question 35

issues with climate change n the Western Desert:

Answer 35

- average temp is 27 degrees celsius - in the summer it can reach 50 degrees celsius - farmers cant work outside - plants+ animals have to cope

Question 36

issues with population in the Western Desert:

Answer 36

- decreases in rural areas and increasing in cities- not enough space - not enough opportunities in rural areas

Question 37

what is causing decertification?

Answer 37

- climate change- forcing people out of desert fringes - resulting in overpopulation as people are starting to live longer - results in overgrazing - results in overcultivation

Question 38

how to reduce the risk of desertification:

Answer 38

- water and soil management - tree planting - use of appropriate technology

Question 39

what is water and soil management?

Answer 39

- low rock walls called bunds constructed along contour lines, interrupting downslope low of surface water

Question 40

example of where water and soil management is being used:

Answer 40

- Sahel- Burkina Faso - Middle East- Jordan

Question 41

concept of tree planting:

Answer 41

- acts as an umbrella, protecting the soil from rain - provide shade for seedlings - roots help to bind soil together

Question 42

examples of tree planting:

Answer 42

- That Desert, India- plant Prosopis Cineraria - African Union- great green wall- Southern Edge of the Sahara Desert

Question 43

concept of appropriate technology:

Answer 43

- alternative cooking devices- small amounts of charcoal - low walls

Question 44

example of appropriate technology:

Answer 44

- charities such as Practical Actich