3.A - Sahel CS

Question 1

Background

Answer 1

• African drylands
• covers 10 nations
• UNEP and ICRAF declared Sahel as ‘mission impossible’ because of climate change and variability

Question 2

ICRAF

Answer 2

International centre for research in Agroforestry

Question 3

physical geography threats to Sahel

Answer 3

• drought
• climate
• winds
• soils
• albedo effect

Question 4

droughts threats to the Sahel

Answer 4

• high periods of droughts = low productivity and biodiversity
• soil cannot support agriculture
• only adapted plants survive eg: Xerophytes

Question 5

measures to mitigate against droughts

Answer 5

• irrigation to manage effects of salinisation

- contour stone barriers: slows run-off, increases infiltration and captured sediment enables groundwater recharge

Question 6

climate’s threat to Sahel

Answer 6

• rainfall patterns impact water availability
• winter - harder rainfall = saturated soils/ increased erosion
• summer - increase rates of evapotranspiration

Question 7

measures to mitigate against climates threats to Sahel

Answer 7

• storage of water during wet periods in ‘planting pits’
• planting of more drought tolerant GM crops
• GM crops do contain suicide gene and are expensive = not totally efficient

Question 8

winds threats to the Sahel

Answer 8

• low vegetation = increased winter winds remove moist air around plants and soils
• evaporation and soil erosion increased = silt, clay and organic matter removed resulting in infertile soil

Question 9

measures to mitigate against wind threats

Answer 9

• vegetation barriers

- grass species form a barrier to wind and water erosion

Question 10

soil’s threat to Sahel

Answer 10

• loss of vegetation = decreased deposition and accumulation of organic litter in soil cultivation = organic matter lost
• erosion - sandy soils

Question 11

measures to mitigate against soil threats on Sahel

Answer 11

• ‘planting pits’
• collects water organic matter added to increase soil fertility
• planting nitrogen-fixing tree eg: Acacia
• farm management = regenerating veg called ‘the re-greening of the Sahel’

Question 12

albedo threats to Sahel

Answer 12

• albedo reflects sunlight heat
• light coloured surface reflects
• atmosphere absorbs reflected heat = temps increase
• temp increase = few clouds and less rainfall = desertification

Question 13

measure to mitigate against the albedo in Sahel

Answer 13

• re-greening projects

Question 14

human geography threats to the Sahel

Answer 14

• population
• deforestation
• overgrazing
• land grabbing

Question 15

population threats to Sahel

Answer 15

• 920M 2014 = approx 1840M by 2050
• increasing at a decreasing rate
• decrease in infant mortality and slow decrease in fertility
• population will exceed carrying capacity

Question 16

measures to mitigate against population threats

Answer 16

• accelerate the demographic transition due to decrease population
• decrease family size
• increase contraception
• increase legal age of marriage

Question 17

deforestation threats to the Sahel

Answer 17

• increase deforestation for fuelwood and an increasing population and settlement growth
• increases wind and water erosion and decrease organic matter
• leads to landgrabbing and overgrazing

Question 18

mitigation measures against deforestation

Answer 18

• agro forestry

- afforestation projects

Question 19

overgrazing threats to the Sahel

Answer 19

• population increase = overuse of land to grow crops

- no recovery time = infertility and crops decrease

Question 20

mitigation measures against overgrazing

Answer 20

• education: farmers increased productivity and decreased land degradation
• increased investment on irrigation
• diversifying crops: drought resistant crops
• trees and bushes = natural fertilisers
• land regeneration

Question 21

land grabbing threats to the Sahel

Answer 21

• increased interest in Sudan acquisitions allowed for UAE, Saudi Arabia, China etc
• displaced indigenous farmers and no legal lans tenure or negotiating rights
• increased mitigation and increased droughts and famine

Question 22

mitigation measures against land grabbing

Answer 22

• increase legal rights of farmers to land ownership