Isabel Balmer 12D
Population Density: A Simple Concept?
Population density refers to the number of people in relation to the space occupied by them. The
simplest measure, crude density of a population, is the number of people per square kilometre or other
unit area and is calculated by:
Total Population
Area of Land Occupied
Calculating the population density can be useful for small units, such as counties or parishes, however
it is of no use when applied to national states or continents where internal environmental conditions
vary significantly and therefore, the data is inaccurate or misleading. More refined density measures
may be calculated; however, even these have problems and inaccuracies.
Many problems exist for geographers trying to establish comparative population densities for different
regions. In theory, a population density map should provide a useful starting point for the study of
human geography in any area because of the way in which the varying densities of people on the land
reflect the relationships between human societies and their environments. Population density maps are
graphical illustrations of how and where people live in relationship to the landscape. However, in
practice, the physical and environmental features of the landscape and man’s interaction with them are
overlooked.
Firstly, there are problems with establishing the number of people in a given area. There are two main
ways in which countries such as the UK count their inhabitants: all births, deaths and marriages have
been officially recorded since 1837, however, it was not until 1875 that it became an offence for people
to fail to register. These records, in theory, would provide an accurate count of the population, but only
if the numbers of immigrants and emigrants were also officially registered. Not only is there an
unknown number of illegal immigrants, but there is also no accurate record of the number of people
leaving the country to settle abroad, (this will apply to other countries apart from the UK) so, although
the number of people in a country or given area can be estimated using the official records, it is
impossible to tell the exact number.
The second method of counting people and gathering information is by conducting a regular census (in
the UK this is every 10 years and has been carried out since 1801, except for 1942 because of the
Second World War). Teams of census enumerators are supposed to deliver a census form to every
address in the country; however, there are many problems with this:
 May not include people in hospitals, shelters or those who are homeless
 Does not include illegal immigrants
 There are problems for people who are illiterate, or do not speak the country’s language and
therefore cannot understand the census form (in the UK, this is solved by issuing various
different copies in different languages, or people are sent out to talk to people with disabilities,
for example, the blind, but this is very expensive and time consuming and many countries
cannot afford it)
 The census may not be returned for various reasons, for example, if someone is not paying tax
(although in the UK this is illegal and there is a fine for not returning a census form)

People may lie, again possibly because they do not want to found, or cross-checked with
records (again, in the UK, lying is an offence)
 It may not necessarily be practicable to deliver a census to every known residence, for
example, in Australia, there are people who live in very remote areas which are not easily
accessible or for which there is no track
 Nomadic people will not be registered, so therefore, it will not be known where they are
 Squatters and people who live in the favelas will not receive a census because it is in the
county council’s interest to disown them so that they do not have to provide electricity, fresh
water, a sanitary disposal system, roads etc. and also so that the immigrants living in the
favelas can do all the jobs that nobody wants to do and get paid a fraction of the minimum
wage for that country because they are not registered as part of the country






Gypsies and New Age Travellers (people with no fixed abode and who do not pay tax) will
not receive a census because they are not registered and have no fixed abode so there is no
way of knowing where they are anyway
Censuses go out of date and conducting them every 10 years is not regular enough to account
for subsequent demographic changes, for example, internal and external migration
Censuses are prone to error as they only count the people who are at their residence on the
night it is conducted. They exclude visitors and tourists and people who are away from their
usual residences, but include students who may be away at college for the night, for example,
in 1991, the census taken of London stated that there were 6,679,699 usual residents, however,
the following morning, London’s population would have swelled by a further 600,000
commuters from outside the city. These commuters are people who work and spend money in
London and use the roads, undergrounds, buses and other services in the city. They also add to
the air pollution, litter and possibly crime, so it is argued that these people should be counted
as well
Censuses only give information on where people are at night, but the Government and
geographers are also interested in where people are in the day. Some people argue that this is
more important because it is when people have the most impact on the environment and
interact with the most people
Census information varies significantly in its accuracy for different parts of the world, for
example, people living in mountainous areas that are not easily accessible may not receive a
census form, or, LEDCs may not have the money to provide people to go and talk to the
illiterate population or those who have disabilities and therefore is not always the most
suitable form for effective population mapping
Censuses (and maps of the world) presume that people stay in the same place and work on that
assumption, however, this is not true.
Another problem for geographers trying to establish comparative population densities for different
regions is that people cannot be counted as directly comparable units, for example, men and women
differ in the amounts of calories they need each day to ensure they stay healthy – men need 2500,
whereas women only need 2000 calories, so already it can be seen that in this instance, men have a
larger pull on resources. Food requirements also vary for people in different climatic regions; for
example, the Inuit will eat food that helps to keep them warm whereas people in warmer climates will
not be using the same resources because they do not need to keep warm. People of different ages and
different dietary habits will also eat differently and therefore use different resources.
The land element in the population density equation is not as simple as it seems at first sight because
there are many problems with the amount of people who live on and farm the land and those that use
the resources that come from it for example, population densities of a city are denser than those where
the land is mountainous and the relief steep because in the cities there are jobs and employment
available, good infrastructure, communications and other services, whereas mountainous land is not
easily accessible, there are very limited employment sectors (sheep grazing is mainly all),
communication is limited and infrastructure is poor, if any at all. Because of this, there is more reason
to live in the cities because a higher standard of living and quality of life is almost certainly guaranteed.
A number of measures are used to assess land area, each with a different method and each producing
different results.
There are four main methods used to establish the people-land relationship of population density, each
with their advantages and disadvantages:
1.
The first method uses the total land area in relation to the total population, which is know
as arithmetic density. This is the simplest and crudest form of measuring population
density as it overlooks the detail of the land and the different densities of people on that
land. Even in traditional societies dependant on subsistence agriculture (a form of
agriculture where all the produce goes to feed the household and is not for sale) there are
technical problems in assessing the total land area, for example, should one include an
inter-tidal zone or the sea when assessing the total land are? Some people may argue that
it should be included if it is used for produce (sea food or fertile silts) because it is being
used as a resource, however, if it were not used, does that area of land have any relevance
to or affect the people-land relationship?
Most problems arise from the differences in land quality because a more fertile land will
produce more resources and have higher economic value than a low quality land. The
differences in land quality are caused by variations in the soil, vegetation, the gradient of
slopes (if in fact, there are any slopes at all) and the climate of the area. All these factors
affect the quality of the land and if one of these variables in a region is different to
another region, the quality of the land will probably be different and therefore, the
resources gathered from the land (depending on what the land is used for) will be
different.
However, total land area is the easiest source of data for the “land” element of the
population density ration. Arithmetic mean is only really useful as a crude generalisation
as it does not take into account the distribution of people in relationship to the land.
2.
The second measure of calculating the population density is the physiological density.
This is calculated by relating the total population to the area of arable land (land
cultivated for crops). However, there are problems with this method as well, because it
cannot be assumed that all of the population is supported by the area within which it has
been counted as the arable land it is being related to may not be producing the resources
for that population. In traditional societies, this method may work, for example,
subsistence farming, however, the method is invalid in any society which is highly
urbanised or dependant on manufacturing and trade because obviously the land cannot be
farmed as it is urbanised. It is also most likely that the society is importing most of their
resources as the surrounding areas cannot support the numbers of people in the society
and that the main trade for the area will be in factories or businesses of some sort.
3.
The third method is agricultural density and this method attempts to avoid the above
problems, still assuming however, that it is subsistence farming. Agricultural density
relates the rural population to the amount of agricultural land it contains, however to
many people, to live in a rural area is an attraction and higher quality of life and many of
the people living in the area will not farm the land but be commuters to the cities. In
China though, many people who live in urban areas have agricultural occupations so
because they do not live on the land but only farm it, they are not included in the
calculation so the results will be inaccurate (the same goes for including people who live
in rural areas but do not farm the land, for example, in the UK and USA). Agricultural
density, therefore, is difficult to use in making comparisons between areas with different
cultures.
4.
The fourth method is called residential density and this is much more useful and accurate
for urban areas. Often, the arithmetic method is used to compare the population densities
of different cities and how these cities are distributed and factors affecting that, however,
for urban areas, it is often more appropriate to relate the total population of, for example,
a city, to the amount of land used for residential purposes, therefore, this will not include
commercial, industrial and park land or transport networks (i.e. roads). If the quality of
life is also an issue, then a better measure may be the number of people per habitable
room (the information would be gathered from a census, so the calculation relies on the
census information being correct), however, this also cause problems because some
families or people may deem a higher quality of life is to have many rooms which in
which there is not always a person in, however, other people may prefer to have all of
their close relatives living with them. This is sometimes the situation with young or
expecting mothers as they may require an extra “hand” to help them with housework and
everyday life, in which case, their parents may live with them. Another example is the
elderly who need special care or help, so for them, having more people in the house to
help them and keep them company would be a higher quality of life. Therefore, it is not
so easy to assume that a higher quality of life necessarily means living in a large houses
with not many people as different people have varying concepts on what makes their life
better.
It can be seen that it is not so easy to just calculate the population density of an area because there are
many different factors that affect it. There are also problems when comparing densities with different
areas because the factors affecting the densities may be different and this has to be taken into account.
The term carrying capacity is a measure of the number of people an area of land can support before any
increase of people brings about worsening conditions or degradation.
The term optimum population, has a similar meaning to carrying capacity, however, it is not the same.
Optimum population is the theoretical number of people, which, when working with all the available
resources and levels of technology and is therefore getting the most out of the land, will produce the
highest standard of living and quality of life. (Standard of living is usually measured by how much a
person earns, whereas quality of life is measured by, for example, the person’s surroundings, i.e. rural
or urban, the services available and in some parts of the world, whether the person is literate or not.)
The optimum population density is partly down to what society values the most, for example, some
people may think that living in a city in a modern and luxurious apartment would increase their quality
of life because they are where “life” takes places and in the centre of all the hubbub and parties,
whereas, another person may prefer to live in the countryside in a little cottage in a village where there
is a strong sense of community spirit and where it is peaceful with very little pollution of any
description. How good a person’s quality of life is also depends on their age, for example, a youthful
person (20-30) may prefer the city night-life and the atmosphere of a city that never sleeps, whereas an
elderly person is more likely to prefer a quiet village which is close to a town or small city where they
can use any services they need and get their living needs and any help that they may need because they
prefer the rural setting and community spirit of a close-knit community.
Carrying capacity can have an affect on the optimum population density because then an area is over or
under populated and therefore not getting the most out of the land economically. (Overpopulation
exists where there are too many people in an area relative to the amount of resources and to the level of
technology locally available, to maintain a high standard of living. This means, that if there were no
change in the level of technology and natural resources locally available, a reduction on the number of
people in the area would result in a higher standard of living and, therefore, quality of life.
Overpopulation is measured by low per capita incomes, high unemployment and under employment
and outward migration.)
Under population occurs when there are too few people in an area to use the available resources and
levels of technology efficiently and to the highest economic value. This means, that if the population
were to increase then there will be a better use of resources and so an increased standard of living for
all the population because the resources are being used to their greatest potential. This would most
likely result in a higher quality of life for the whole population.
It should not be assumed, however, that just because one area is successful in supporting a particular
density of people (per square kilometre) that another area with a lower density cannot be overpopulated
because whether an area is overpopulated or not depends on the quality of the land involved and the
resources it has the potential to produce. Also, different people will have different consumer
requirements; for example, a Polynesian islander and a farmer in the American Mid-West are very
different and therefore, so are the demands they make upon the land, industry and trade. It is also
necessary to allow for the differences in the efficiency of people as producers when comparing areas of
different cultures as food is not only the requirement of humans and different societies vary in how
their economies are self-contained. So far, no general method has been acceptable enough to equate
people as producers.
However, for the optimum population density there are a few methods that can be used to specify the
optimum population densities, which are:
I. One of the methods is known as the ecological optimum. This is the density that can be
supported by natural resources without destroying them, i.e. sustainable development:
“Development that meets the needs of the
present without compromising the needs of
the future. It takes into account social
welfare, economy and environment”
On a global scale, humans have already exceeded the ecological capacity of the world and a
commonly asked question is, “Can the planet support the total population (which is
increasing) without famines and people starving?” Theoretically, yes, it is possible to produce
the food, however, the concern is that since most of the additional food production comes
from irrigated land, (the action of artificially supplying land with water to help the growth and
productivity of plants) will there be sufficient water to continue to meet the demand? Another
concern is that although it is theoretically possible to produce sufficient food for everyone,
will the consequences to the environment be disastrous and if so, is it possible to produce food
via a sustainable method? Again, this causes problems to arise, such as whether it is necessary
to for all the natural elements of the world to be maintained.
Other problems that there are from exceeding the ecological capacity (and therefore the
carrying capacity) are that consequences may include famine, (as mentioned above) disease;
extinction of specie; cutting down of the tropical rain forests; global warming and the fossil
fuels running out (which already are). If the world is not made more sustainable, then the
extinction of species will cause a collapse of food chains and hence the collapse of ecosystems
which would be disastrous to human life as it would affect them.
II. A different approach takes an economic perspective. The economic optimum is taken to be the
number of people that yield the highest per capita output. However, any further growth in the
population will fail to bring a proportional increase in production, of which decreasing returns
will be the result. However, the same can be said in the reverse: if the population falls below
the optimum, economies of scale will be lost (the lowering of unit costs achieved by
increasing the scale of production). Therefore, a reduction in population will cause a
disproportional decrease in average output per head and so reducing the average standard of
living per head and not performing to the economic optimum.
The economic optimum assumes that no changes in technology will take place, however, it
has been the case that shortages of resources have encouraged appropriate technological
advances so that the problem can be sorted. However, in this world, the level of technology is
constantly changing and technological advances are being made. Another difficulty is the use
of the term “optimum”, may imply a society that shares the rewards and outcome of high
productivity, however, this is not the case. There is nowhere in the world where everything is
shared and everyone has equal status – every society has a hierarchical structure of some form,
therefore it is probable that a small few may have a disproportional share of the benefits. This
means that there may be an optimum but not for many people, therefore, the concept of having
an economic optimum population is just a theory.
The optimum population density would be to have a perfect carrying capacity that allows the given
resources and local level of technology to achieve their potential. This would allow a higher standard of
living because the area of land is producing the highest economic value and therefore people will be
paid more and the area will be more affluent through trading the resources produced but keeping
enough to provide for the local society. Because the society is richer, then there is most likely to be a
high quality of living because the population can afford all their everyday living needs as well as
having luxuries. However, some people may argue that quality of life is not governed by your standard
of living. It may be argued that just because a person has enough money and material wants and can
afford to live in an area that appeals to them, they may not be happy and therefore their quality of life
will not be high. Many people are more likely enough to judge their quality of life on objects and
concepts that cannot be bought, for example, family love, friendship and happiness, although, to be
happy and fully appreciate the above concepts then a one needs enough money to get by relatively
easily and not have to worry that there is not enough money to pay the bills.
So, although carrying capacity and optimum population density are linked, especially if a high quality
of life is achieved by being rich and through getting the most out of the land, optimum population
density is also down to interpretation, whereas carrying capacity is a fact: the land can support a certain
number of people efficiently and comfortably – this cannot be changed by interpretation
Population density does have a value in the study of population geography, because there are
generalisations that can be drawn from it. Population density shows the amount of people occupying a
certain area of land, and that, along with population distribution, (the way in which people are
distributed in a given area) general conclusions can be drawn into why and how people live where they
do. If a closer study then looks into the affluence of the area and the strengths and weaknesses it has,
i.e. levels of pollution or crime, then this information can be related back to the environment and the
people-land relationship.
Population density does have a place, however, it is important to understand that it is not accurate and
that there are many factors influencing it, for example, about two thirds of the world’s population still
relies on agriculture so, areas that are unsuitable for farming remain sparsely populated. Low-lying
areas, especially temperate zones, are more densely populated and areas capable of producing high
yields also have very high densities of population.
Although population density does have a place when studying population geography it is important to
realise that just because an area has a high population density, it does not mean that the densities are
evenly distributed and that the whole area has a high population density because the distribution of the
world’s population is very uneven with some areas being very densely populated while others are
almost totally uninhabited, For example, about 80% of the world’s population lives between twenty
and sixty degrees north of the Equator, however, this area also contains some of the world’s largest
mountain ranges – areas with very sparse populations because they are unsuitable for most things i.e.
very difficult to access, no communication lines, not suitable for agriculture, slopes to steep for grazing
animals etc. It also includes some of the desert land where the climates are too hot for farming and
grazing as well as there being little vegetation for cover (as well as to hold the earth together), droughts
and unsuitable soil, as it is very sandy and not very rich in nutrients.
The physical and human factors that affect population density can make it difficult to compare different
regions. As mentioned above, the world’s population distribution and densities are unevenly spread
across the land surface, but so too are wealth, food, medical care, water supplies and other socioeconomic and political factors. Changes in population densities (and distributions tend to be because of
technological advances and political factors, therefore, this has to be taken into account when regions
are being compared that have different levels of technology, or different political arrangements.
Not all measures of population density are valueless, however, for comparisons to be made between
regions of different population densities, different environments, economies, cultures, political factors
and human activities have to be taken into account. Population density can have a useful value when
studying the population and the people-land relationship of a given area that has the same culture
throughout and is of limited size, with no huge irregularities of the physical landscape and economy
because on a limited scale, many of the problems that arise from measuring population density can be
reduced, for example, arable land can be more easily defined on a smaller scale, however, realistically,
there can be no universally applicable population density measure calculations because humans do not
live in a universally similar world.
References
A. Bowen and J. Pallister (2000)
“AS Level Geography”
Chapter Four
Heineman
Lancaster Geography Poster 10
Phillip Allan
“Geography Review January 2000”
Phillip Allan Updates
Audrey N. Clark (1992)
“Dictionary of Geography: Human and Physical Geography Terms Explained”
Logman