GCSE · Geography · AQA · Spec 8035

Causes of desertification

Picture a field that fed a village for years. No desert moves in, yet slowly it turns bare, dry and useless. What could possibly do that?

Build the web

Five causes, one destination

Desertification is fertile land turning into desert. Link the factors below: which one makes another happen, or makes it worse? Start from the causes and follow them towards the bare soil at the end. Watch out for population growth — think about how it does its damage.

Population growth
Cutting trees and shrubs for fuelwood
Overgrazing by livestock
Over-cultivation of crops
Climate change bringing more drought
Plant cover is lost
Bare soil is eroded and loses its nutrients (outcome)

Add a link

This factor……made this happen or worse

No links yet.

What it really means

Is it just deserts getting bigger?

The word 'desertification' makes a lot of people picture the Sahara creeping outwards like a tide of sand.

Which is closest to what you think desertification is right now?

It's when an existing desert grows and swallows the land next to it.It happens inside deserts, where the land is already dry.It's an African problem — the rest of the world isn't at risk.It's fertile land slowly becoming desert, mostly in dry land that borders a desert.

How sure are you?

I'm sureI think soI'm guessing

It's when an existing desert grows and swallows the land next to it.

This is a common misconception

It's a natural guess — the word sounds like 'desert spreading'. But desertification is the land itself turning into desert. Fertile land becomes increasingly arid (dry) because of climate change, deforestation or unsuitable farming. The damage happens to the land where it is.

It happens inside deserts, where the land is already dry.

This is a common misconception

Flip that round: the land at risk is land that is not desert yet. Desertification can happen to any fertile land that becomes increasingly arid. It mainly hits arid and semi-arid land next to existing deserts, where the ecosystems are fragile and rain is already limited and seasonal.

It's an African problem — the rest of the world isn't at risk.

This is a common misconception

The Sahel, just south of the Sahara, is the largest area at risk. But land at risk exists on every continent except Antarctica. Even in Europe, southern and eastern Spain are at risk.

It's fertile land slowly becoming desert, mostly in dry land that borders a desert.

This matches the evidence

Exactly. Those borderlands are most at risk because their ecosystems are fragile and their rain is already limited and seasonal, so there's little room for things to go wrong. The Sahel is the largest area at risk, but there is land at risk on every continent except Antarctica — including southern and eastern Spain.

Think 'land degrading', not 'desert spreading': fertile land becoming arid, mostly in fragile dry land next to deserts.

The process

What happens once the plants go?

Put the stages of desertification in the order they happen

1 · First stage4 · Last stage

The soil loses its nutrients through leaching, so it can support less plant growth
Vegetation cover decreases
Less plant litter returns even fewer nutrients, so fewer plants can regrow
With no roots holding it together, the soil is eroded by wind and rain

Two farming causes, side by side

OvergrazingvsOver-cultivation

Look for the row where they differ most.

Focus

What's going on

Overgrazing

Livestock such as cattle, sheep and goats feed on the land's plants

Over-cultivation

Crops are farmed so intensively the land gets no time to recover

The insight

Both are farming: one with animals, one with crops.

What gets used up first

Overgrazing

The plants: animals eat them faster than they can grow back

Over-cultivation

The soil's nutrients: crop after crop uses them up

What happens next

Overgrazing

The land is stripped of vegetation

Over-cultivation

The soil becomes infertile, so crops struggle to grow

Where it ends

Overgrazing

Soil left unprotected against erosion and nutrient loss

Over-cultivation

Soil left bare and vulnerable to erosion

Climate change

Reason it through

How can a changing climate push fertile land towards desert?

Link 1 of 4

First link · your turn

Temperatures rise and rainfall patterns change. What happens to droughts?

Locked — reveal the link above first

Your turn

Write it, then mark it

Explain how human activities can cause desertification in an area such as the Sahel. [4 marks]

Your answer

0 words · your answer stays on this page and is not sent anywhere.

The mark scheme

Population growth increases demand for land, food and resources (1 mark)
Trees and shrubs are cut for fuelwood, removing the roots that hold the soil (1 mark)
Overgrazing: livestock eat plants faster than they grow back, stripping the vegetation (1 mark)
Over-cultivation uses up soil nutrients, leaving the soil infertile so crops struggle (1 mark)
With vegetation cover lost, the exposed soil is eroded by wind and rain (1 mark)
The soil loses nutrients through leaching, so fewer plants can grow back (1 mark)

Model answer

Human activities remove the plant cover that protects the soil. As the population grows, as it has quickly in the Sahel, demand for land, food and resources rises, and in the Sahel farming has spread into fragile, dry areas. Livestock such as goats and cattle overgraze the land, eating plants faster than they can grow back — a major cause of desertification in the Sahel. Where trees and shrubs are cut down to burn for fuel, their roots no longer hold the soil together, and where crops are farmed too intensively the soil's nutrients are used up and it becomes infertile. With the vegetation cover gone, the exposed soil is eroded by wind and rain and loses its nutrients through leaching, so fewer plants can grow back.

Any four of these points earn the marks — but only when each cause is carried through to what it does to the plants or the soil.

Exam line: For every cause, keep going until you reach the soil: cause → plants lost → soil exposed → eroded and short of nutrients.

WHAT YOU'VE LEARNED

A quick recap of today's lesson.

Five very different causes. One patch of bare, dying soil.

What you need to know

Desertification is the process by which fertile land becomes desert, due to climate change, deforestation or inappropriate farming.
It mainly affects arid and semi-arid land next to existing deserts, where ecosystems are fragile and rainfall is limited and seasonal.
The Sahel, south of the Sahara, is the largest area at risk; land at risk exists on every continent except Antarctica, including southern and eastern Spain.
The stages: vegetation cover decreases → soil is eroded by wind and rain → soil loses nutrients through leaching → fewer plants regrow.
Five causes: fuelwood deforestation, overgrazing, over-cultivation, climate change and population growth.

The big picture

Desertification is the process by which fertile land becomes desert, through climate change, deforestation or inappropriate farming. It mainly affects dry land next to existing deserts, such as the Sahel. Once plant cover is lost, roots stop holding the soil together, wind and rain erode it, it loses its nutrients, and fewer plants can grow back. Fuelwood cutting, overgrazing, over-cultivation and climate change each lead into that process, and population growth drives three of them.

Key points

1Desertification is fertile land becoming desert — not an existing desert spreading.

2Every cause leads to the same thing: soil left bare, eroded and short of nutrients.

3Fuelwood cutting removes trees and shrubs, and with them the roots that hold the soil.

4Overgrazing strips the plants first; over-cultivation uses up the soil's nutrients first.

5Climate change works through drought: faster evaporation, drier soil, less vegetation.

6Population growth drives fuelwood cutting, overgrazing and over-cultivation, and in the Sahel it has pushed farming into fragile, dry areas.

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Worked example

Problem

Explain how cutting trees and shrubs for fuelwood can lead to desertification.

⚠ Watch out

Naming a cause instead of explaining it. 'Overgrazing causes desertification' stops too early. Carry the chain through: animals eat the plants faster than they regrow, so the soil is left bare, eroded and short of nutrients.

🧠

Memory hook

No plants, no roots. No roots, no soil. Every cause of desertification is just a different road to bare ground.

✓

Check yourself

Cover the page. Can you name all five causes of desertification, and say which cause does its damage by driving three of the others?

Flashcards

(12)

What is desertification?

The process by which fertile land becomes desert, due to climate change, deforestation or inappropriate farming. It can happen to any fertile land that becomes increasingly arid.

What kind of land is mainly affected by desertification?

Arid and semi-arid land next to existing deserts.

Why is dry land next to deserts so vulnerable?

Its ecosystems are fragile and its rainfall is already limited and seasonal.

Where is the largest area at risk of desertification?

The Sahel, just south of the Sahara.

Is desertification only a problem in Africa?

No — land at risk exists on every continent except Antarctica, including southern and eastern Spain in Europe.

Once vegetation cover is lost, why does the soil erode?

There are no roots left holding it together, so wind and rain carry it away.

How does less plant litter make desertification worse?

Less litter returns even fewer nutrients to the soil, so fewer plants can regrow.

Who cuts trees and shrubs for fuelwood, and why?

Communities, often in low-income countries, who burn the wood for fuel.

How does overgrazing cause desertification?

Livestock such as cattle, sheep and goats eat plants faster than they grow back, leaving the soil unprotected. It is a major cause in the Sahel.

How does over-cultivation cause desertification?

Crops are farmed so intensively that soil nutrients are used up, the soil becomes infertile, crops struggle and the bare soil erodes.

What is a drought?

A long period with little or no rainfall.

How does population growth cause desertification?

It raises demand for land, food and resources, so land is deforested, overgrazed and over-cultivated.

Tap any card to flip it, or use Study as deck to go through them one at a time. In the full lesson these run as a spaced-repetition deck — you rate each card Hard, Good or Easy and the tricky ones keep coming back until they stick.

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Five causes, one destination

Is it just deserts getting bigger?

What happens once the plants go?

Write it, then mark it

More AQA GCSE Geography topics