Living World - Hot Deserts Desertification

Question 1

desertification

Answer 1

process where land gets drier & degraded bc climate change/human activities

Question 2

semi arid

Answer 2

climate that recieves 250mm - 500m rain per year

Question 3

sahel location

Answer 3

southern edge of sahara

Question 4

causes of desertification

soil erosion

Answer 4

caused by overcultivation/overgrazing = topsoil exposed = reduced interception = intense rain can wash away soil = no veggie supported :(

Question 5

causes of desertification

removal of fuel wood

Answer 5

reduced interception = increased soil erosion = ability to let veggie grow decreases

Question 6

causes of desertification

climate change

Answer 6

less rainfall since 1970 = increased temp = reduce soil quality = salinization + the veggies :(
(may be natural rainfall cycle or human induced)

Question 7

causes of desertification

overgrazing

Answer 7

veggies eaten = exposed soil = reduced infiltration = higher runoff = reduced fertility = less veggies

Question 8

causes of desertification

over cultivation

Answer 8

aquifers being used to irrigate
nutrients used from soil = reduced fertililty

Question 9

causes of desertification

population growth

Answer 9

• 30m, 1950 –> 1bn, 2050
• bc refugees fleeing conflicts, increased fertility, improved health
• = more intense farming, increased deforestation for fuel wood, more livestock

Question 10

salinisation

Answer 10

1. rapid evap of water
2. leaves salf
3. affects ferility

Question 11

strategies to reduce desertification

magic stones

Answer 11

• small stone walls built along contours = reduced runoff = increases ability of soil to help veggies by 50%
• water collected by walls irrigates shrubs = binds soil = supports veggies :)

Question 12

strategies to reduce desertification

great green wall

Answer 12

• projects plans to plant trees on southern edge of sahara
• tree roots stabilise soil + increase fertility (increased leaf litter)
• provide shade = reduced evapo
• creates jobs and stimulate political stability

Question 13

strategies to reduce desertification

appropriate technology

Answer 13

• more sus option bc its local reliant
• efficient stove made from eg clay = reduced fuel wood need = reduced deforestation
• can generate electricity
• solar energy can also be used