Factors that affect the Spheres of influence

The city of Harare has the largest sphere of influence. Image credit

ZIMSEC O Level Geography Notes: Settlements:Factors that affect the Spheres of influence

The most important factor in determining the sphere of influence of a settlement is it’s size
Products and services can also be used to determine a settlement’s sphere of influence for example a product that is only produced in a given settlement increases that settlement’s sphere of influence
Frequency with which a good and service is required and its cost determine the distance people have to travel to buy it
The sphere of influence of a particular product or service is thus also determined by its cost
Goods and services that are cheap and frequently required are usually bought by people around the settlement for example bread, beer and newspapers
Higher order goods are less frequently required and cost more
These therefore have a larger sphere of influence since people have to travel longer distances for them
Only larger towns and cities can successfully support higher order gods and services
Spheres of influence for a good and service can be mapped to show the extent of urban influence or a town’s sphere of influence
The case study of the city of Gweru is used here to explain this concept
Four services, namely, the distribution of bread from a local bakery, bulky beer from a local brewery, furniture from a local furniture shop and the distribution of a local weekly newspaper were selected
These were used to try and determine the sphere of influence of Midlands province’s capital, Gweru
Bread a fairly perishable product, which is frequently required by customers has the smallest sphere of influence
It is therefore a low order product
The highest sphere of influence is reflected by furniture, a less frequently required, expensive and a more durable product
This makes it a high order product
The brewery and weekly newspaper have a medium sphere of influence
These are less frequently required products compared to bread but perhaps more frequently required than furniture
Availability of goods and services extends further along communications lines than areas that are less accessible
Spheres of influence are also affected by affluence (abundance of money that is, riches/ wealth), consumer tastes and preferences
Modern populations have the capacity to travel longer distances to purchase goods and services than was possible in the past
This extends the sphere of influence of cities than would have otherwise been possible in the past
Government policy and planning can also affect spheres of influence of modern towns and cities
Decentralisation of services from the city centres can result in them losing customers to small urban centres.
For example the creation of Growth Points in Zimbabwe
Smaller centres have also be known to lose their traditional low order functions to large cities where goods are cheaper as a result of low transport costs and economies of scale
In spite of all these influences the general influence of the size of settlement on its sphere of influence still holds for the majority of settlements in Zimbabwe and the world over.
Thus the city of Harare still has the largest sphere of influence followed by Bulawayo