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Population - Geography Form 4


By the end of the session you should be able to define population, population distribution, density and demography.


Factors influencing population distribution in East Africa.

The factors influencing population distribution in East Africa can be classified into four main groups.

  • Physical
  • Historical
  • Economical
  • Political

We now discuss each of the mentioned factors.

Physical factors

These factors include climate and relief. The two most influential elements are rainfall and temperature. Very high temperatures like those experienced in Lowdar and around Lake Magadi discourage human settlement likewise extremely low temperatures such as those experienced on high slopes of Mt. Kenya discourage settlement.


Places receiving rainfall of over 1000mm are densely populated. The abundant rainfall favours the production of both food crops and cash crops. For example the Kenya highlands.


  • Areas of high altitude have low population because of low temperatures, very steep terrain where soil erosion is rampant it is difficult to construct roads and house and landslide occur. Plains and gently sloping areas attract more settlements. For example the lake Victoria plateau in East Africa. The very flat areas experience poor drainage which results in swampy conditions or flooding. This discourages settlement.


  • Dense forests are sparsely populated because they habour wild animals and pests which can be a danger to human habitation livestock and crops. So most forested areas are sparsely populated for example Kakamega forest, miambo woodlands of Tanzania and Lambwe valley are infested with tsetse flies which has discouraged human and livestock habitation. The grasslands on the other hand are easier to settle on, farm and built roads.


  • Generally fertile soils like rich volcanic soils and alluvial soils attract human settlement in large numbers. This explains the high population in Kenya highlands with volcanic soils and around Lake Victoria with alluvial soils. On the contrary infertile leached soils and water logged soils have sparse population because they are agriculturally unproductive.

Historical factors

The next group of factors is historical factors.

  • The areas affected by slave trade in the 18th century have continued to have light or sparse population because of displacement of many people who were scattered to North America, West Indies and South America.
  • Colonization also had its effects. The African reserves introduced for Africans had high population which kept increasing while the lands taken away for plantation farming had sparse population. Tribal conflicts and wars have led to some places becoming sparsely populated e.g. between Kuria and Maasai in Kenya.


      Economic factors

      Economic factors also play a big role in population distribution. Places where mineral s are found or industries set up normally built up heavy settlements , people come for employment and provision of other services for example Magadi town, Mwandui in Tanzania and Kasese in Uganda.

      Political factors

      Many places which experiences political unrest force large groups of people to migrate to other places. For example the influx of refugees from southern Sudan, Somali, and Uganda in the 70s increased population where they settled in Kenya. While areas of origin remain sparsely populated. Sometimes government projects displace people into new settlement areas. For example during the construction of Ndakaini dam and the Sondu Miriu power project, gazetted National parks and forest reserves prohibit human occupation in such areas.
      After independence the former white highlands were subdivided as high density and low density settlement. The low density remains sparse with high density settlement has many people.

      Provide a photograph of urban settlement with industries for example Thika town.

      Population growth.

      Population in most places tends to increase in number but it can also decrease. This is what is referred to as population growth. Population growth can be referred to as positive growth when there is an increase in number or negative growth when there is a decrease.The population growth is calculated as either natural or numerical growth.

      Natural growth

      This is described as the natural increase or decrease in population basing on the crude birth rate and crude death rates.Crude birth rate is the estimated rates of births in a rear. The crude birth is calculated by dividing the total numbers recorded in a year by the total population in that year and multiplying the fraction by 100. For example,

      Numerical population increase

      This increase is calculated based on ten years census records; it can be expressed in percentage. For example. Population 1989 was 21,443,636
      Population 1999 was 28,686,607.Inter censal increase= 7,242,971(the difference between the two census)

      Numerical growth gives real increase in population since it considers births and deaths ignoring migration, natural growth on the other hand focuses on births and deaths, ignoring migration.

      On the other hand the crude death rate is calculated using this formulae.

      Factors Influencing Population Growth

      The factors that influence population growth include fertlity and Mortality.


      This refers to the number of live births a woman has during her productive period. Some women experience primary infertility (childlessness) or secondary infertility (failure to conceive after getting one or two children). There is also voluntary infertility where conception is deliberately prevented.
      Fertility rate in a given population is the average number of children that a woman of child bearing age will have in her life time. The high fertility rate in Kenya has been due to improved nutrition, improved health service, and weakening of traditional customs. The fertility rate in Kenya in 1979 was eight children, 1989, 6.6 and 1999 is 5. This clearly shows declining fertility rate.


      This is number of deaths in a given population. The death rate or mortality rate is the number of deaths per 1000 per year. These deaths rates can be classified as,

      1. Child mortality rate which refers to the number of deaths of children aged between 1-5 years per 1000 births.
      2. Infant mortality rate refers to the number of deaths in first year of life per 1000 live births.
      3. Adult mortality rate refers to number of adults dying per 1000 of the total population. Mortality is of significance because it reduces the population in a given area.

      Mortality may be caused by an outbreak of war, famine, floods or epidemics.The death rate in many countries including Kenya is declining. This is due to improved medical care.


      Sometimes people change their residence permanently or on temporary basis. This movement is described as migration.It involves movement of people into a country i.e. is immigration and the people moving in are called immigrants. On the other hand emigration is where people leave their native land for another country. They are called immigrants.

      Migration can be international or internal.Kenya has experienced emigration with influx of refugees from Uganda, Sudan and Somalia. Increasing population in Kenya and reducing in the source countries

      Causes of migration

      Migration is caused by push and pull factors. Some of the factors include the following;

      Pressure on land.

      Availability of employment opportunities.


      Natural calamities

      Government policy:

      Forced migration.

      Availability of employment opportunities.

      Job opportunities attract many people to other countries or towns for example there has been an influx of workers from the neighboring countries to the mining towns in South Africa. In Kenya many people have moved to Nairobi and Mombasa in search of employment.Plantation farming in developing countries has attracted people from their rural homes.


      Wars, religious and political conflicts create suffering and even death necessitating migration of many people to secure places or countries.

        Natural calamities

        Natural disasters include disease outbreak, floods, severe drought and volcanic eruption. Many people move to more secure places for people and animals.

        Government policy

        large scale development projects by the government may necessitate compensation and relocation of people to create room for the project. For example the mining of titanium in Kwale has already displaced many people.

        Forced migration.

        This type of migration involves force transfer of large numbers of people for political, religious or racial reasons for example criminals from Britain were exiled to Australia. Asians in Uganda were expelled by Idi Amin and the 17th and 18th century slave trade transferred many people from west and East Africa to Latin America, USA and west Indies.

        Pressure on land

        Agriculturalists may be forced out of their land or country when the land becomes too small to support the crops or livestock. In Kenya many people moved from Kisii, Kakamega, Kiambu, Nyeri to Rift valley and Coast regions.

        Types of migration

        The two types of migration are internal and external.

        Internal migration

        Internal migration involves movement of people within a country due to pull or push factor.There are four forms of internal migration;

      • Rural to urban migration
      • Rural to rural migration
      • Urban to rural migration
      • Urban to urban migration

      • Rural to urban migration

        Where people move in search of jobs, entertainment, and education.

        Rural to rural migration.

        It involves migration of people from rural are to another rural area for employment in an industry or plantation.

        Urban to rural migration.

        Some migrants move from urban areas to rural areas on job transfer, failure to secure employment or increased insecurity in urban areas.

        Urban to urban migration.

        This type of migration occurs when people move from one town to another in search of better employment or business opportunities.

        External migration.

        The second type of migration is external migration.
        This is the movement of people from their own countries to other countries. It is also called international migration. The migrants require a passport and visa in order to control this movement. Many people migrate in search of better jobs, for education, to provide specialized skills and on special arrangements e.g.. The Green card to U.S.A

        Effects of migration

        Effect on the place of origin

        Migration from rural areas leads to reduction of population from place of origin causing shortage of labour. It also leads to imbalance in the sex-ratio since in most cases a majority of the migrants are men.
        There is a tendency of leaving behind the old, the women and children who are less productive.

        Effect on the destination

        Destinations of migration experience an increase in population. If the immigrants are involved in gainful employment the area may develop due to increased production. On the other hand if the immigrants fails to secure employment may result to many crimes. The resultant increase of immigrants creates pressure on existing infrastructure, high cost of houses, leads to growth and expansion of slums.

        Effect on individual

        Migration can have both positive and negative effect on an individual for example loss of cultural values or improved standards of living.

        Population structure

        Population structure refers to the composition of a given population in terms of age and sex at a particular time. This information is got during census. The data is compiled and the number of males and females of every age is obtained. The information is commonly presented using an age-sex population pyramid.
        The shape of the pyramid can bring out the stage of development of a country.

        Significance of population structure

        The composition of a population has important implications about a country's development, for example:

        • planning
        • calculation of dependency ratio
        • calculation of sex ratio.

        Calculation of dependency ratio.

        The dependency ratio is the proportion of the population that is unproductive population to the productive. The unproductive population includes children under 15 years of age and old people over 65 years of age. The productive group is the working population between 15 and 64 years.The dependency ratio of a country can be calculated as follows:

        If the dependency ratio is high the number of dependants is high, few resources will go to development of the country since consumption is allocated a bigger share.

        In some areas in Kenya the number of dependants is increasing on daily basis as the working people succumbs to the HIV/AIDS pandemics.

        Calculation of sex ratio:

        Sex ratio is the number of males per 100 females. If the ratio shows 100 males more than females e.g. 105:100). This explains social problems in such a population. On the other hand of the ratio is less than 100 (95:100) then there is male deficiency which is a far reaching effect on fertility.


        The government can formulate policies for social economic development after the breakdown of population by age and sex. For example the government determines how to allocate funds for the youth and the elderly especially for education, health and social welfare programmes.

        Consequences of population growth

        The consequences of population growth vary according to the demographic stage of a country.The consequences are captured in the demographic trends. Demographic or population trends are changes resulting from population growth in different phases.


        Over population is a situation where by a region or country has a population that it cannot be supported fully due to a strain on the available resources.Among the problems that arises from over population are:

      • Underdevelopment
      • Unemployment
      • poor housing and health facilities
      • Underutilization of agricultural resources
      • Slow industrial growth
      • increased bias in traditional attitudes
      • Effect on Gross Domestic Product(GDP)
      • Underdevelopment

        Rapid population growth leads to underdevelopment due to a large proportion of children who are dependent on the relatively small working population. The large number of young people puts an extra strain on the social amenities e.g. education facilities


        In overpopulated countries industrialization is slow, training facilities are few and therefore few jobs are unavailable for the skilled and unskilled workers.In such areas rural to urban migration is rampant leading to unemployment and under employment.

        Poor housing and health facilities

        The standard of living is usually low in over populated countries. Slum settlements are wide spread especially in urban areas.The standards of nutrition and general hygiene are low.This leads to malnutrition and the spread of diseases. The overwhelming number of people leads to a massive strain on the available social amenities.

        Underutilization of agricultural resources

        A Large population may lead to shortage of land and land fragmentation, this situation coupled with use of traditional techniques and inadequate finance to purchase in puts and misuse of marginal lands lead to low production

        Slow industrial growth

        This generally arises from a large but unskilled labour force and many people with low purchasing power discouraging expansion

        Increased bias in traditional attitudes

        Large populations mainly in developing countries are conservative regarding to artificial birth control, introduction of new crops and education.This attitude leads to slow development

        Effect on Gross Domestic Product (GDP)

        Gross domestic product is the value of all goods and services produced in a country within a specific period. Over population makes it difficult for a government or community to invest in productive activities keeping the (GDP) down or even to decline.This lowers the standard of living in the country. A big population however can be advantageous by providing a large market for goods and services and a source of cheap labour

        Under population

        Under population is a situation where by there are too few people to fully develop the economic potential of an area or nation

        The consequences of under population include:

      • Uneven distribution of population
      • In some areas the population density is very low such that the acute shortage of labor and the resources lie unexploited.

      • Scarcity of amenities, under populated areas remains underdeveloped since it is uneconomical to provide services like communication health and education.Sometimes the available amenities and resources are underutilized because of small number of people
      • Inadequate market A small population cannot guarantee a large market for goods especially when the purchasing power is low. A small population may also lead to slow expansion in agriculture
      • High transport cost The cost of transportation is hiked to compensate for unoccupied seats. This hinders internal trade and people tend to concentrate on subsistence production. Other transport problems may include delays and overloading
      • Related study of Kenya and Sweden

        The comparative table of facts given presents a summary between the two countries

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