Sahara Desert case study for GCSE Geography

The Sahara is the world's largest hot desert and a commonly taught case study for the hot desert section of Paper 1 (Section B, The Living World). AQA allows centres to choose which hot desert to study, but the Sahara is a popular choice because resources, mark schemes, and exam exemplars frequently use it. It covers around 9 million square kilometres across North Africa and spans 11 countries, including Algeria, Egypt, Libya, Mali, and Sudan. For GCSE you need to know its climate, plant and animal adaptations, the development opportunities it offers, and the challenges of developing it.

This guide gives you the named-place facts, the figures examiners reward, and a clear structure for answering the six and nine-mark exam questions on hot deserts.

The Sahara has a classic hot desert climate: Extremely hot days, cool nights, and very little rainfall. Average summer temperatures reach 40°C. The 58°C figure previously cited for Aziziya, Libya (1922) was decertified by the WMO in 2012; the currently accepted world record is 56.7°C at Furnace Creek, Death Valley. Night-time temperatures can fall to near freezing because there is no cloud cover to trap heat.

Rainfall is below 250 mm per year across most of the desert, and many parts receive less than 25 mm. Rain often arrives as short, intense storms that cause flash floods. Humidity is very low, which means evaporation rates are extremely high.

Plants and animals in the Sahara have evolved adaptations to survive extreme heat and a lack of water. Mark schemes reward specific named examples paired with their adaptation, not vague answers about "storing water".

Plants tend to focus on either avoiding water loss (small or waxy leaves), storing water (succulent stems), or reaching it (deep roots). Animals tend to focus on avoiding heat (nocturnal behaviour), conserving water (concentrated urine), or surviving without it for long periods.

The Sahara may be hostile, but it offers real economic opportunities. AQA expects you to know four main categories: Mineral extraction, energy, farming, and tourism. Use named examples for the top band.

Libya and Algeria produce a combined 2.5 million barrels of oil a day or more from Saharan oil fields. Morocco holds around 70 percent of the world's known phosphate rock reserves and is one of the largest producers, supplying global fertiliser markets. The Ouarzazate solar plant in Morocco is one of the largest concentrated solar plants in the world. Tourism around Tunisia and Egypt brings in billions of dollars a year, with desert safaris and Star Wars film locations near Tozeur.

The same conditions that make the Sahara extreme also make development difficult. AQA exam answers should cover four challenges: Extreme temperatures, water supply, accessibility, and the cost of building infrastructure.

Water is the headline issue. Aquifers like the Nubian Sandstone Aquifer System hold huge amounts of water, but pumping it out is expensive and the supply is non-renewable. Roads and rail are limited, with some areas accessible only by 4x4 or camel. Construction costs are inflated because materials and labour have to be transported in.

AQA nine-mark questions on hot deserts usually ask you to assess the opportunities or challenges of developing a named hot desert. The mark scheme rewards a balanced answer with specific named examples and a clear conclusion.

Use a three-paragraph structure: One paragraph on opportunities with two named examples, one on challenges with two named examples, and a short conclusion. Each paragraph should link back to the question wording. End with a judgement, not a summary.

Question: Using a named example, assess the extent to which the opportunities of developing a hot desert outweigh the challenges. (9 marks)

Model answer opening: The Sahara, the world's largest hot desert, offers significant economic opportunities but also presents serious challenges. Oil and gas extraction in Libya and Algeria produces a combined 2.5 million barrels a day or more, providing major export income. The Ouarzazate solar plant in Morocco generates 580 MW of clean electricity, enough to power 1 million homes.

However, water scarcity is the biggest challenge. Libya's Great Man-Made River cost around £20 billion to build and pumps non-renewable fossil water that will eventually run out. Extreme temperatures of 40°C and limited road access drive up construction costs and limit the workforce. Overall, opportunities outweigh challenges for countries with the capital to invest, but small-scale development remains very difficult.