Test yourself on Hot Deserts with exam style questions, marked instantly.

Flashcards that come back just before you would forget them.

A revision plan that remembers what you know and shows what to do next.

See which topics you have nailed and which need another look.

🧠 The CACTUS Mnemonic

Six letters for everything you need to know about hot deserts:

Letter	What It Stands For	Key Fact to Recall
C	Climate — arid conditions, extreme temperature range	<250mm rain; 20°–30° latitude; diurnal range up to 50°C; Hadley Cell subsidence explains location
A	Adaptations: plants and animals with specific mechanisms	Saguaro: pores open only at night + accordion stem; Camel: oval blood cells + 30% dehydration tolerance; Fennec fox: 15cm ears radiate heat; Ephemeral seeds: dormant for decades
C	Challenges — water, heat, dust, inaccessibility	Thar: 50°C summer max; loo winds; wells drying up; 25% of India land degraded; dust storms killing 100+ in 2018
T	Thar case study — opportunities for development	Bhadla Solar Park: 2,245 MW (world's largest); Indira Gandhi Canal: 649km, 2m hectares irrigated; Jaisalmer tourism: 1.5m visitors; 80% of India's gypsum from Rajasthan
U	Unsustainable pressures — drivers of desertification	7-step cascade: population growth → overgrazing → over-cultivation → deforestation → climate change → soil erosion → desertification; 12 million hectares lost per year globally
S	Solutions — stone bandi, FMNR, Great Green Wall	Stone bandi: 300,000 hectares, +50–80% crop yield (Burkina Faso); FMNR: 5m hectares, 200m trees (Niger); Great Green Wall: 8,000km, 15m hectares completed so far

Plants: Store, Reduce, Reach (store water in stems / reduce surface area / reach deep groundwater)

Animals: Avoid, Concentrate, Store (avoid heat through nocturnal behaviour / concentrate urine / store fat reserves)

Make this stick

Signing in gives access to all PrepWise features.