Factors that affect the Spheres of influence

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

• 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

To access more topics go to the O Level Geography Notes page