Case Study - Thar Desert / Sahel

Question 1

Background (Thar Desert)

Answer 1

Border between India and Pakistan in S. Asia
More people planning to live in desert due to increasing population

Question 2

Distribution of world’s hot deserts

Answer 2

Subtropics; between 20-30 degrees N/S of the Equator
Tropics of Cancer and Capricorn run through most of the world’s hot deserts

Question 3

Major characteristics of hot deserts

Answer 3

• aridity (annual rainfall < 250mm)
• heat (>40 C)
• landscapes - mostly rocky with thorny bushes, though some have dunes

Question 4

Hot deserts inhabitants

Answer 4

• people live in large open tents to keep cool
• food cooked slowly in warm sandy soil
• head scarves provide protection from the sun

Question 5

Climate

Answer 5

• less than 250mm rainfall per year
• may rain once every 2-3 years
• 50C in the day, 5C in the night (averages)
• occasional frost and snow in winter

Question 6

Annual rainfall

Answer 6

~250mm

Question 7

Average temperatures (day and night)

Answer 7

50C in the day
About 5C in the night

Question 8

Cactus - adaptations

Answer 8

• widespread roots absorb water soon after rainfall (e.g., saguaro cactus roots spread 15m in each direction, but only 15cm deep)
• needles instead of leaves reduce surface area, and therefore, transpiration

Question 9

Camels - adaptations

Answer 9

• humps help to store fat
• wide feet for walking on sand
• long eyelashes to protect from sand

Question 10

Desert interdependence

Answer 10

Different parts of the ecosystem are closely linked together and depend on each other, especially in such a harsh environment

Question 11

Opportunities for development

Answer 11

• valuable minerals for industry and construction
• energy resources e.g. coal, oil
• renewable energy, such as solar power at Bhaleri
• tourists attracted, especially during festivals

Question 12

Challenges for development

Answer 12

• extreme heat makes it difficult to work outside for long periods of time
• evaporation rates from irrigation canals and farmland
• limited water supplies struggle to sustain increasing population
• roads are difficult to build and maintain

Question 13

Causes for desertification (Sahel)

Answer 13

• fuel wood
• over-cultivation
• climate change
• overgrazing
• population growth

Question 14

Desertification - fuel wood (Sahel)

Answer 14

The removal of trees by people needing fuel causes the soil to be exposed

Question 15

Desertification - over-cultivation (Sahel)

Answer 15

If crops are grown in the same area too often, nutrients all get used up causing soil erosion

Question 16

Desertification- climate change (Sahel)

Answer 16

Less water is available for plants, due to reduced rainfall and rising temperatures

Question 17

Desertification - overgrazing (Sahel)

Answer 17

Too many plants are eaten faster than they can grow back, due to the high number of animals

Question 18

Desertification - overpopulation (Sahel)

Answer 18

More pressure is put on the land by people needing resources, causing deforestation, over-grazing and over-cultivation

Question 19

Strategies to reduce desertification (Sahel)

Answer 19

• water management
• tree planting
• technology
• soil management

Question 20

Reducing desertification - water management (Sahel)

Answer 20

Growing crops that don’t need much water

Question 21

Reducing desertification - tree planting (Sahel)

Answer 21

Trees can act as windbreakers to protect the soil from wind and soil erosion

Question 22

Reducing desertification - soil management (Sahel)

Answer 22

Leaving areas of land to rest and recover lost nutrients

Question 23

Reducing desertification - technology (Sahel)

Answer 23

Using less expensive, sustainable materials for people to maintain e.g., magic stones