Global Population Distribution and Demographics
Population distribution refers to where people live.
Although environmental conditions influence, there is no one “best” climate and the proof is that most people live in South-East Asia, which has a monsoonal climate with hot, wet seasons and hot, dry seasons. The key to explaining population distribution is the ability to support–i.E. Feed- a population.
Areas with resources can feed people; those without, cannot. Other humanfactors as political, economic or even historical are also important. POpulation Densi: is the number of people per km². The same factors affect population density as affect population distribution, such as supply of water, fertile soils, raw materials and good communications. At a global scale, three major areas of high population density (with over 200 people per km²) can be identified; SouthEast Asia,NorthEast USA,Western Europe. DIstribution facts on a global scale: Unequaldistribution. The average population density in the world is 50 hab / km². Only30%oftheEarth is permanently inhabited, the rest is almost empty . 75%ofthepopulation live within 1000 km of the sea. 85%live in areas less than 500 m high. 85%live in Eurasia between latitudes 68ºN and 20ºN. Less than 10%live in the southern hemisphere. Themostpopulated countries are LEDCs; MEDCs only have 25% of the world total. Favorab location: Fertile valleys, such as the Nile and the Ganges valleys →Places with regular supply of water, as in the British Isles Favorable locations Demographic deserts →Areas with temperate climate, as the Mediterranean →Regions with goodcommunications, as Germany or the USA. Demographic desert: Areas with less than 1 inhabitant per km2 (Oceania) →Deserts (they are too dry for crops and food) →Mountains (they are too steep to have enough arable land) →Rainforest (their soil are often infertile for crops) →Highlatitudes (the Poles are too cold for human living). 1. THE MOST POPULATED AREAS ▪ East Asia: East China, Korea, Japan, Taiwan. ▪ South Asia: India, Indochina, Philippines, Malaysia. ▪ Europe: especially the industrial corridor England-Holland-France-Germany-Italy. ▪ North America: East coast of the USA, New England and St Lawrence valley. 2. MEDIUMPOPULATEDAREAS ▪ Conurbations: South-East Brazil (Río de Janeiro-Sao Paulo), Río de la Plata (Buenos Aires-Montevideo), The Guinean Gulf (Lagos), Down Nile (El Cairo Alexandria), Singapore and the Isle of Java. ▪ Areas with sprawling population: California, South Texas, The Mexican Plateau, the Caribbean region, The Maghreb, The Persian Gulf, Russia and East Australia. 3. THE LEAST PO ▪ Major deserts: Arizona, Patagonia, Sahara, Kalahari, Arabia, Karakum, Kavir, Gobi, Taklamakan and Australia. ▪ TheEquatorial zone: the Amazon basin and Central Africa. ▪ Otherareas: Oceania, the Poles and the highest mountain ranges. RACIALDISTRI: Races are distinct genetically divergent populations within the same species with relatively small morphological and genetic differences. These differences mainly deal with color skin, height, cranium shape, facial features and blood type. In the USA they classify races into the following groups: White, Black, Asiatic, Hispanic and other minorities
POP STRUCTURE: To knowabout population growth it is necessary to calculate several rates concerning natality, fertility and mortality in a country during a period of time.▪Birth rate:
Average annual number of births during a year per 1,000 persons.▪ Death rate: average annual number of deaths during a year per 1,000 persons.▪Natural increase:
The difference between the birth rate and the death rate. This increase does not take into account migrations.▪Infant mortality rate: number of children under 1 year old that die during a year per 1,000 live births. ▪Total fertility rate: average number of children that would be born per woman. FACTS ABOUT NATURAL INCREASE. Ancient demography has both birth and death rates at a high level. Modern demography has both birth and death rates at a low level. Depending on the historical era populations can be classified into three types: → Expanding populations = uncontrolled natural increase → Stationary populations = constant birth and death rates → Contracting populations = natural increase is zero. The evolution from the first one to the second one is denominated the Demographic Transition. It starts with a significant decrease of death rates, follows with a progressive decrease of birth and fertility rates and ends with a stabilization of every rate. The Demographic Transition is related with the Epidemiologic Transition which is a progressive declining impact of mortality caused by plagues and diseases. There are two factors that influence in these two transitions: ▪Biological factors: age structure, sex ratio, environmental conditions. ▪ Socio-cultural factors: living standards, healthy habits, social position of women, contraception, religion, culture, demographic policies, etc. POP STRUCTURE: refers to its composition and characteristics. This include age, sex ratio and occupational structure and it is represented visually through a graph called population pyramid. In a population pyramid age groups are signified as bars with a different length depending on their number. Age groups are usually classified as young (<15 years old), adults (15-65) and old people (>65).
By analyzing a population pyramid it is possible to deduce other demographic aspects such as birth and death rates, life expectancy, number of labor force and the effects of migrations or catastrophes. However, there are other issues concerning population composition that cannot be comprehended through a pyramid such as ethnicity, languages and religions. The shape of a pyramid also shows the transition stage in which a country is, as you can see above./Developed countries had their baby boom in the 1950s and 1960s but then reduced their birth rates to stay in aged demographic profiles, especially in Europe. Developing countries have experienced uncontrolled population growth in the 20th century, accounting for 4/5 of the world’s total population. They are expected to reduce their birth rates in the 21st century. What is coincidental in both cases is rural exodus and a high increase of urban population. That leads to the creation of large conurbations or urban agglomerations, where it is more difficult to ensure an adequate provision of public services, social welfare, a rational occupation of geographical space and the conservation of traditional culture. Today, the largest megacities on the planet are located in the Third World. This situation is the basis for the spread of pessimistic theories about the future of world’s population, according to the classical ideas of T. R. Malthus. He predicted in 1803 a progressive shortage of food on Earth because men tend to multiply faster than the available resources. / we can classify populations into two types: 1.Post-transitional populations (Europe, USA, Canada, Australia & NZ, Japan, South Korea, Taiwan, Singapore): slow natural increase, low birth, death and fertility rates, too many old people, massive immigration coming from LEDCs. 2. Transitional populations (Asia, Africa, Latin America & Caribbean): rapid increase, declining mortality, still high infant mortality rate, too many young people, massive emigration to MEDCs. CHALLENGES to the world population: World economic unbalance and poverty. Extremely high population growth in LEDCs. Population ageing in MEDCs. Inequality between male and female population. Demographic impacts of wars. The case of refugees. Newinternational migrations. Globalization. Urbanization increase. Environmental problems 10. Others