The four key concepts (+ scale)

Whatever option you take, examiners want you to argue through the DP's four key concepts:

• Places — locations have distinctive physical & human characteristics; meaning is given to them by people.
• Processes — the physical and human mechanisms (e.g. erosion, migration) that change places over time.
• Power — who has the ability to influence and control places, flows and decisions (governments, TNCs, communities).
• Possibilities — the range of futures and management options; geography as a subject about choices.

Scale matters: the same issue looks different at local, national, regional and global scale. Strong answers move deliberately between scales and use located examples.

Choosing your themes

The seven optional themes are:

• Freshwater — drainage basins, hydrology, flooding and water management.
• Oceans & coastal margins — ocean-atmosphere systems, coasts, resources and governance.
• Extreme environments — hot arid/semi-arid lands and cold/high-altitude periglacial areas.
• Geophysical hazards — earthquakes, volcanoes and mass movement, and the risk they pose.
• Leisure, tourism & sport — participation, tourism systems and their futures.
• Food & health — food systems, disease diffusion and wellbeing.
• Urban environments — urbanisation, urban systems and liveability.

Exam shape: at SL you answer on two options in Paper 1 (1 h 30). At HL you take three (2 h 15). Each theme ends with a possibilities-style question about futures and management.

Which key concept?

Freshwater — drainage basins

A drainage basin is an open system with inputs (precipitation), stores (soil, groundwater) and outputs (evapotranspiration, river discharge). The water balance equation links them:

A storm hydrograph shows discharge after rain. A short lag time and high peak (a "flashy" hydrograph) points to steep, impermeable or urbanised basins — the physical processes that raise flood risk.

Possibilities: hard engineering (dams, levées) vs soft strategies (afforestation, floodplain zoning). Who benefits and who bears the cost is a question of power.

Your turn — water balance

Oceans & coastal margins

Oceans move heat and carbon around the planet (currents, the thermohaline circulation) and shape coasts through waves, tides and sediment.

• Constructive waves build beaches; destructive waves erode them.
• Longshore drift transports sediment along the coast; a sediment budget weighs inputs against outputs.
• Governance: oceans beyond national waters are a global commons — overfishing and plastic pollution are classic power and management problems.

Places link: coral reefs and mangroves are highly productive but vulnerable to warming and acidification — connect this to the Global Change core.

Extreme environments

The IB defines two types: hot, arid & semi-arid environments (deserts, their margins) and cold & high-altitude / periglacial environments.

• Distinctive processes: aridity, salinisation, freeze–thaw weathering, mass movement on slopes.
• Human adaptations: nomadic pastoralism, irrigation, tourism and mining bring both opportunity and pressure.
• Possibilities: desertification and permafrost thaw are managed differently by rich and poor communities — a scale and power issue.

Which family of themes?

Tap a term, then tap the theme family it belongs to.

Geophysical hazards & risk

Earthquakes, volcanoes and mass movements are hazards; they become disasters only when they meet vulnerable people. The IB frames this as:

The recurrence interval of a hazard from records is:

Power & possibilities: the same magnitude quake kills far more where building codes, warning systems and wealth are weak — vulnerability is socially produced, not just physical.

Your turn — recurrence interval

Hazard or disaster?

Leisure, tourism & sport

This theme studies why participation in leisure varies, how tourism systems work, and their futures. A key model is Butler's resort life-cycle (TALC): exploration → involvement → development → consolidation → stagnation → then rejuvenation or decline.

Because tourist numbers often grow at a steady percentage each year, we can estimate doubling time with the rule of 70:

Possibilities & power: carrying capacity, leakage of tourist spending to foreign firms, and "overtourism" are the sustainability debates the exam rewards.

Your turn — doubling time

Food & health

This theme links food systems (production, trade, security) to health outcomes and the geography of disease.

• Food security — availability, access, utilisation and stability; famine is usually about access and power, not just supply.
• Disease diffusion — how illnesses spread (expansion, relocation, hierarchical diffusion) across scales.
• The epidemiological transition — a shift from infectious diseases to non-communicable "diseases of affluence" as places develop.

Places link: the same crop yield can mean food security in one place and hunger in another — access and entitlements matter as much as production.

Urban environments

Over half the world now lives in cities. This theme covers urbanisation, urban systems and liveability.

• Processes: urbanisation, suburbanisation, counter-urbanisation and re-urbanisation.
• Challenges: informal settlements, the urban heat island, traffic, and unequal access to services — a "food desert" is an urban access problem.
• Possibilities: smart, resilient and eco-city strategies for sustainable urban futures.

Match the clue to its option

Tap a clue on the left, then its matching theme on the right.

Name the transition

Reading themes through concepts & scale

Top answers don't just describe a theme — they interrogate it with the concepts and move between scales:

• Places: use a named, located example, not "a country".
• Processes & power: explain the mechanism and who controls it.
• Possibilities: weigh strategies and reach a justified judgement.
• Scale: show how the issue differs from local to global.

Command terms: "examine", "evaluate" and "to what extent" all want a two-sided argument and a conclusion — not a list.

Spot the strong answer

The big ideas to know

You've toured all seven Paper 1 options and the concepts that unlock them. Press Finish to see your score.