IGCSE Geography / Fragile environments and climate change

Case study: desertification of the Sahel revision notes

Edexcel International GCSE Geography (4GE1), chapter 7: Fragile environments and climate change, specification point 7.1b, 7.2a. Free lesson.

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The Sahel is a semi-arid belt south of the Sahara where drought and human pressure on the land have caused desertification. Knowing its causes, impacts and key figures helps you explain this case study.

Where the Sahel is and why it is vulnerable

The Sahel is a semi-arid belt, meaning it is dry but not quite desert. It runs along the southern edge of the Sahara, from Senegal to Sudan. Rainfall is very low and mostly falls during a short rainy season, so crops and livestock are vulnerable when the rains fail. Countries in the Sahel include Senegal, Mali, Burkina Faso, Niger, Chad and Sudan. The driest parts receive as little as 100 mm of rain a year, mostly from June to August. All six countries have a low HDI (Human Development Index), so they are developing countries. Niger's population grew from 3.5 million in 1960…

How physical and human causes led to desertification

Drought is the physical cause. It began in 1968, with severe drought returning from 1983 to 1985. Scientists mainly link the droughts of the 1970s and 1980s to changes in sea temperatures. Human activity did not cause the drought, but it made the damage worse and helped turn drought into desertification. Drought: In the dry years after 1968, crops had almost totally failed by 1972 and at least half the livestock were lost. Population pressure: More people needed food, so more land was farmed. The soil was not given time to rest and lost fertility. Fuel supply: Trees and scrub…

How desertification affected people and livelihoods

The impacts followed a chain: less food was produced, people became malnourished, famine caused deaths, and families migrated. This created both social impacts and economic impacts. Reduced agricultural output: crops had almost totally failed by 1972. Malnutrition: in 2012, over 1 million children were at risk. Famine: about 100,000 people had died by 1973. Migration: families moved to towns or across borders when their land could no longer feed them. This added pressure to the places they moved to. Malnutrition, famine and migration are social impacts. Lost crops and…

How to explain the causes using Niger

For a named developing country question, identify one physical cause and one human cause, then explain how each damaged the land. Include a relevant year or figure to support your explanation.

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