Key Idea: Topic 13.1 is about why a city is not laid out at random — why shops, offices, factories and housing each end up where they do. Its single micro pulls three strands together: Land values & bid-rent — the price of land peaks at the Central Business District (CBD) and falls outwards, so the activity that can pay most wins the most accessible, most expensive site. Land-use models — the concentric (Burgess) rings and the sector (Hoyt) wedges are two simple maps of how those zones sort themselves out. Why activities locate where they do — physical (flat, coastal land), economic (land value, accessibility) and political (planning, zoning, regeneration) factors decide the detail. This is Option G (Urban environments) content, examined on Paper 1. SL students answer two options and HL three (the same questions), each ending in a 10-mark Examine/Evaluate essay marked on markbands.
🏙️ Land values & bid-rent — the spine of the topic
The single most important idea in this topic is land value: the price (or rent) of land is highest at the CBD and falls with distance towards the urban edge. This is the bid-rent idea — each land use will only pay so much for a site, and the highest bidder wins. High-footfall retail and offices out-bid everyone for the costly core; housing and industry are pushed out to cheaper land. The skill examiners test is to read a bid-rent graph or urban map, describe the falling trend (quote a figure with units), then explain why land values vary and why each activity sits where it does.
Land value and the activity that wins the site, by distance from the CBD
| Distance from CBD | Land value (index, peak = 100) | Activity that can pay |
|---|---|---|
| 0 km (CBD / peak land-value point) | 100 | Shops, offices, banks — high footfall, need accessibility |
| 1 km (inner city) | 55 | Older flats, small workshops, some retail |
| 3 km (inner suburbs) | 30 | Terraced and semi-detached housing |
| 6 km (outer suburbs) | 15 | Detached housing, schools, parks |
| 10 km (urban edge) | 8 | Industry, warehouses, retail parks — need cheap, spacious land |
Read the axes first: where is the curve steepest, and what is the land value at 3 km?
🔒 Interactive diagram
Explore the labelled diagram, charts and maps for this topic in study mode.
Key terms for land value
- CBD (Central Business District) — the commercial core (shops, offices, banks); the most accessible point.
- Land value — the price or rent of a piece of land. Highest at the CBD, falling outwards.
- Peak land-value point (PLVP) — the single most expensive site, usually a main CBD junction.
- Bid-rent — each land use will only pay so much for a site; the highest bidder gets the most accessible land.
- Accessibility — how easy a site is to reach; high accessibility raises demand and so land value.
Tip: For a bid-rent graph or urban map, describe the trend first — land value is highest at the CBD (index 100) and falls to about 8 at the edge, with the steepest fall in the first 3 km. Quote a figure with units. Then explain it with accessibility and bid-rent.
📐 The land-use models — Burgess rings & Hoyt sectors
Two classic models summarise how the zones sort out. Burgess (concentric) sees land use in rings around the CBD; Hoyt (sector) improves on it by adding wedges that follow transport routes. Both are simplifications — examiners want you to use them as a framework, then add the role of physical site and planning.
Concentric (Burgess) vs sector (Hoyt) models
| Feature | Burgess (concentric) | Hoyt (sector) |
|---|---|---|
| Shape | Rings around the CBD | Wedges (sectors) out from the CBD |
| Main driver | Distance / age of housing | Transport routes (roads, rail, rivers) |
| Industry | An inner transition ring | A wedge following a rail or river corridor |
| Housing | Gets newer/larger outwards | High-cost housing forms its own wedge on attractive land |
| Strength | Simple link of value to distance | Adds the pull of transport and physical site |
Burgess — rings around the CBD
- Ring 1 — CBD: shops, offices; highest land value.
- Ring 2 — inner city / transition: old industry and low-cost housing.
- Ring 3 — inner suburbs: older terraced housing.
- Ring 4 — outer suburbs: newer, larger housing on cheaper land.
- Ring 5 — urban edge: commuter zone, industry, retail parks.
Hoyt — wedges along routes
- Land use grows in wedges (sectors) out from the CBD, following transport routes.
- Industry follows a rail or river corridor — cheap, flat, well-connected land.
- High-cost housing forms its own wedge on attractive land (hills, away from industry).
- Improves on Burgess by adding the pull of transport and physical site.
🌍 Why activities locate where they do — real cities
Land value sets the broad pattern, but physical, economic and political factors decide the detail. Examiners want the mechanism — name a factor, then explain how it pushes an activity to a site. Always develop the chain, never just list.
Factors that decide where an economic activity locates
| Factor type | Example factor | How it shapes the location |
|---|---|---|
| Physical | Flat land / relief | Industry and airports need flat, cheap land — steep slopes and floodplains are avoided |
| Physical | Coast / river site | Ports and old industry cluster at the waterfront for transport and water |
| Economic | Land value / bid-rent | Only high-profit retail and offices can afford the costly CBD; housing and industry move out |
| Economic | Accessibility | Retail wants high footfall at the CBD; warehouses want motorway junctions on the edge |
| Political | Planning / zoning | Councils zone land, protect green belt and grant or refuse permission, fixing where uses can go |
| Political | Regeneration policy | Government schemes re-use old docks or factories, changing a district's function |
Example: In Barcelona, the flat coastal plain held the dense grid-iron CBD, while industry took the level land by the port — a physical control. Planning then converted the old industrial seafront for the 1992 Olympics into housing and leisure — a political control reshaping land use. In Singapore, tight government zoning deliberately places industry on reclaimed coastal land and high-value finance in the CBD — land use here is planned, not left to the market.
Example: In Lagos (a fast-growing megacity), formal jobs are too few for the population, so a vast informal economy — street trading, small workshops, repair stalls — fills the gap, clustering on cheap, accessible roadside land. In Detroit, the collapse of car manufacturing left huge areas of derelict factories and housing — when the economic activity that paid for the land vanished, the land use emptied out.
Key terms for economic activity
- Economic activity — retail, commercial (offices), industry, services and housing.
- Informal economy — small-scale, unregistered work (street trading, workshops) common in fast-growing cities.
- Zoning / planning — council rules fixing which land uses can go where (a political control).
- Regeneration — re-using derelict land (old docks, factories) for new functions.
- Green belt — a protected planning ring around a city that limits where activity can spread.
Don't just name a factor — show the chain. Flat coastal land → cheap + accessible → industry locates there. High CBD land value → only retail/offices can pay → housing pushed out.
✍️ IB-style questions
Explain how physical and economic factors decide where industry locates within a city.
🔒 Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
Examine the importance of land values, relative to other factors, in deciding where economic activities locate within cities.
🔒 Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
✅ Quick self-check
Tap each card to reveal the answer.
Why does land value fall away from the CBD? The CBD is the most accessible point, so demand is highest there — and high demand means high value. Move out and accessibility drops, so demand, value and the bid-rent fall.
What is bid-rent? Each land use will only pay so much for a site; the highest bidder wins the most accessible, most expensive land — which is why retail beats housing for the CBD.
Burgess vs Hoyt — what's the difference? Burgess = land use in rings around the CBD (value falls with distance). Hoyt = land use in wedges that follow transport routes out of the CBD.
Why is the informal economy large in megacities like Lagos? Rapid growth and rural-urban migration leave too few formal jobs, so people rely on small-scale informal work (street trading, workshops) to survive.
What does a top [10] Examine answer need? Two or more developed factors (land value, physical site, planning, accessibility), a named city, a weighing of their relative importance, and a clear judgement.
🎯 Highest-yield exam reminders
Exam Tips
- For a bid-rent graph or urban map: DESCRIBE first (highest at CBD, falls to the edge, a figure with units, steepest fall in the first 3 km), THEN explain with accessibility + bid-rent.
- Land value peaks at the CBD and falls outwards — the activity that can pay most wins the most accessible site.
- Burgess = rings; Hoyt = wedges along transport routes. Use a model as your framework, then add physical site and planning.
- Outline/Explain = factor + MECHANISM (flat cheap land → industry; high CBD value → housing pushed out), never a bare list.
- Know your three factor types: physical (relief, coast), economic (land value, accessibility), political (zoning, regeneration).
- On the Paper 1 [10] Examine/Evaluate: develop two+ factors, name a real city (Singapore, Barcelona, Lagos), and finish with a clear judgement.