This topic summary covers Topic Summary: Hot Deserts within Hot Deserts for GCSE Geography. Revise Hot Deserts in The Living World for GCSE Geography with 0 exam-style questions and 22 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 14 of 14 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 14 of 14
Practice
0 questions
Recall
22 flashcards
Topic Summary: Hot Deserts
Key Terms
- Arid: <250mm rainfall/year; evaporation > precipitation
- Diurnal temperature range: Day-night temperature difference (up to 50°C in deserts)
- Hadley Cell: Atmospheric circulation creating desert belts at 20–30° latitude
- Xerophyte: Drought-adapted plant (cacti, acacia)
- Xerocole: Drought-adapted animal (camel, fennec fox)
- CAM photosynthesis: Stomata open at night only — reduces water loss 95%
- Ephemeral: Plant that exists as dormant seed; germinates rapidly after rain
- Desertification: Human-driven degradation of semi-arid land
- Salinisation: Salt build-up in irrigated soils — reduces fertility
- Pastoralism: Livestock herding across seasonal grazing routes
Key Facts and Statistics
- Sahara: 9.2 million km² (largest hot desert); Thar: ~200,000 km²
- Thar population: 83 million (most densely populated hot desert)
- Thar rainfall: 100–500mm/year; 325 days of sunshine
- Bhadla Solar Park: 2,245 MW — world's largest solar farm (2023)
- Indira Gandhi Canal: 649km, irrigates 2 million hectares
- Jaisalmer tourism: 1.5 million visitors (2019)
- Desertification: 12 million hectares lost/year globally; 2 billion people affected
- Stone bandi (Burkina Faso): 300,000 hectares restored; +50–80% crop yields
- FMNR (Niger): 5 million hectares, 200 million trees restored
- Great Green Wall: 8,000km target; 15 million hectares completed (15% of target)
Thar Desert Case Study
- Opportunities: Solar (Bhadla 2,245 MW); tourism (Jaisalmer 1.5m visitors); minerals (80% India's gypsum); irrigated farming (canal)
- Challenges: Water scarcity; 50°C+ summers; dust storms (100+ deaths 2018); inaccessibility; desertification pressure
- Canal costs: Salinisation; downstream water conflict; groundwater depletion; climate risk to Himalayan source
Exam Essentials
- Always name specific plants/animals with specific adaptations — not just "has small leaves"
- Desertification = human-driven degradation, NOT natural spread
- Use the 7-step cascade for 6-mark causation questions
- Balance opportunities AND costs for the Indira Gandhi Canal
- Compare solutions using evidence: stone bandi vs FMNR vs Great Green Wall
- CACTUS mnemonic: Climate, Adaptations, Challenges, Thar, Unsustainable pressures, Solutions