Settlements: Services & Sphere of Influence (Years 7–11) — Geography

Settlements form a hierarchy from hamlet to city, and the size of a settlement controls how many and how rare the services it can support are.

Ask yourself a simple question: why does your nearest village have a corner shop but not a hospital, while the nearest city has both? The answer is not luck. It is a set of tidy geographical rules about how many people a service needs to survive, and how far people will travel to reach it. Learn those rules and you can predict what services almost any settlement will have.

Why this matters — In settlement geography, you're expected to link the size and function of a settlement to its services. Strong answers use the key terms range, threshold and sphere of influence correctly, so these are marks you can bank with clear definitions and good examples.

The settlement hierarchy

A hierarchy is a ranking. We can rank settlements by population and by the number of services they provide. As you move up the hierarchy there are fewer settlements but each is larger and offers more and rarer services.

Hamlet — a tiny cluster of houses, perhaps a farm or two; often no services at all.
Village — low-order services such as a shop, primary school, pub or place of worship.
Town — a range of shops, a secondary school, banks, a market and a health centre.
City — high-order services: hospitals, universities, large shopping centres, cathedrals or major mosques.
Conurbation — several towns and cities that have merged into one huge built-up area.

Up the pyramid: fewer but larger settlements with more and rarer services.

Low-order and high-order services

Services are sorted by how often people use them and how far they will travel for them.

Type	Examples	Bought	Travel
Low-order (convenience)	Newsagent, bakery, post office	Often, daily	Short distance
High-order (comparison)	Hospital, university, furniture shop	Rarely	Long distance

Range, threshold and sphere of influence

Three linked ideas explain the whole pattern:

Range — the maximum distance people are willing to travel to use a service. A daily loaf has a small range; a specialist hospital has a large range.
Threshold — the minimum number of people (customers) needed for a service to open and stay in business. A corner shop has a low threshold; a department store needs a very high one.
Sphere of influence — the whole area served by a settlement or service — the area from which it draws its customers. High-order services have large, overlapping spheres of influence.

High-order services need a high threshold, so they can only survive in large settlements that have enough people within a large range. This is exactly why cities, not villages, get hospitals and universities.

Small village spheres of influence overlap and sit inside the far larger sphere of a city.

Worked example (Explain, 4 marks): "Explain why a city has more high-order services than a village." A high-order service such as a hospital needs a very high threshold population to be profitable (1). A city has a far larger population within the service's range (1), and a large overlapping sphere of influence drawing customers from surrounding towns and villages (1), so the threshold is met — whereas a village cannot supply enough customers, so the service would fail (1).

Common exam mistake: Students swap range and threshold. Remember: range = distance travelled; threshold = number of people needed. Do not describe sphere of influence as "how big the settlement is" — it is the area served, which can be far larger than the settlement itself.

Memory hook: Range = Road (how far you travel); Threshold = Tally of customers. If the tally is too small, the shop shuts.