You are viewing a free preview of this lesson.
Subscribe to unlock all 10 lessons in this course and every other course on LearningBro.
Desertification is the process by which fertile land becomes desert. It is one of the most significant environmental challenges facing the world today, affecting the lives of hundreds of millions of people. For AQA GCSE Geography, you need to understand the causes, impacts, and management strategies for desertification, with reference to specific case studies.
Desertification is the degradation of land in arid, semi-arid, and dry sub-humid areas, caused primarily by human activities and climate change. It is not the expansion of existing deserts — it is the creation of desert-like conditions in areas that were previously productive.
Key facts:
Desertification is most common on the margins (edges) of existing hot deserts, where the climate is already marginal for farming and vegetation:
| Region | Location | Key Detail |
|---|---|---|
| The Sahel | Sub-Saharan Africa (Mali, Niger, Chad, Burkina Faso, Sudan) | The most widely studied example; southern edge of the Sahara |
| Thar Desert margin | Rajasthan, India / Sindh, Pakistan | Case study for AQA GCSE |
| Mediterranean | Southern Spain, North Africa | Increasing drought and over-extraction of water |
| Central Asia | Uzbekistan, Turkmenistan | Aral Sea disaster caused by irrigation mismanagement |
| Australia | Interior of Australia | Drought and overgrazing |
Desertification is caused by a combination of climate change and human activities. In most cases, human activities are the primary driver.
| Factor | Explanation |
|---|---|
| Reduced rainfall | Climate change is making semi-arid regions drier, with less predictable rainfall |
| Increased temperatures | Higher temperatures increase evaporation rates, drying out the soil faster |
| More frequent droughts | Longer and more intense droughts stress vegetation and reduce soil moisture |
| Changing wind patterns | Shifts in atmospheric circulation can reduce moisture reaching marginal areas |
| Cause | Explanation |
|---|---|
| Overgrazing | Too many animals strip the land of vegetation; roots are destroyed, soil is exposed |
| Over-cultivation | Farming the same land repeatedly without rest periods exhausts soil nutrients |
| Deforestation | Cutting down trees for fuel (firewood and charcoal) removes root networks and shelter |
| Population growth | Increasing demand for food, fuel, and water puts unsustainable pressure on marginal land |
| Poor irrigation practices | Over-irrigation leads to waterlogging and salinisation, making soil infertile |
Exam Tip: When discussing causes, you must cover both climate change and human activities. AQA questions frequently ask you to explain both natural and human causes. A common mistake is to focus only on human factors and neglect climate change, or vice versa.
Desertification typically follows a predictable chain of events:
This is a positive feedback loop — each stage makes the next stage worse, accelerating the process.
| Impact | Detail |
|---|---|
| Soil erosion | Topsoil is blown or washed away, reducing land productivity |
| Loss of vegetation | Plants die or fail to grow, reducing biodiversity |
| Water scarcity | Reduced rainfall and increased evaporation deplete water sources |
| Dust storms | Exposed soil is picked up by wind, creating dust storms that damage crops and health |
| Loss of biodiversity | Habitat destruction forces species to migrate or face extinction |
| Impact | Detail |
|---|---|
| Famine and malnutrition | Crop failure leads to food shortages |
| Poverty | Farmers lose their livelihood when the land can no longer support crops or animals |
| Migration | People are forced to leave their homes and move to cities or other countries |
| Conflict | Competition for shrinking resources (water, grazing land) can trigger violence |
| Health problems | Dust inhalation causes respiratory diseases; contaminated water causes illness |
Exam Tip: Desertification is not just an environmental issue — it is a major social and economic crisis. Always include both types of impact in your answers. Linking environmental degradation to poverty, migration, and conflict will demonstrate higher-level understanding.
The Thar Desert (also known as the Great Indian Desert) is located in Rajasthan, northwest India, extending into Pakistan. It is an important AQA case study for both opportunities and challenges of hot desert environments.
| Feature | Detail |
|---|---|
| Area | Approximately 200,000 km² |
| Population | One of the most densely populated deserts in the world |
| Rainfall | 120–500 mm per year (higher in the east) |
| Temperature | Up to 50°C in summer; below 0°C on winter nights |
| Key city | Jaisalmer, Jodhpur, Jaipur (on the desert margin) |
The Thar also provides economic opportunities:
| Opportunity | Detail |
|---|---|
| Mining | Limestone, gypsum, and feldspar are mined commercially |
| Solar energy | Intense sunlight makes Rajasthan ideal for solar power (e.g. Bhadla Solar Park) |
| Tourism | Desert safaris, camel treks, and historic forts attract visitors |
| Irrigation farming | The Indira Gandhi Canal brings water from the Himalayas to irrigate the desert |
| Wind energy | Wind farms have been established in Jaisalmer district |
A range of strategies exist to reduce or reverse desertification. They work best when used in combination.
| Strategy | Description |
|---|---|
| Drip irrigation | Delivers water directly to plant roots, minimising waste and evaporation |
| Rainwater harvesting | Collecting and storing rainwater for use during dry periods |
| Underground dams (sand dams) | Trap water in sandy riverbeds, storing it below the surface to reduce evaporation |
| Borehole management | Controlling the rate of groundwater extraction to prevent water table depletion |
| Strategy | Description |
|---|---|
| Stone lines (bunds) | Lines of stones across slopes slow down surface run-off and trap soil and moisture |
| Terracing | Cutting steps into hillsides to reduce the speed of water run-off and soil erosion |
| Mulching and composting | Adding organic matter to the soil to improve fertility and water retention |
| Crop rotation | Alternating crops to maintain soil fertility and prevent exhaustion |
| Strategy | Description |
|---|---|
| Tree planting (afforestation) | Trees stabilise soil with their roots, provide shade, and reduce wind erosion |
| The Great Green Wall | A pan-African project to plant a belt of trees across the Sahel from Senegal to Djibouti |
| Managed grazing | Controlling the number and movement of livestock to allow vegetation to recover |
| Planting drought-resistant crops | Using varieties that need less water and are adapted to marginal conditions |
Subscribe to continue reading
Get full access to this lesson and all 10 lessons in this course.