Population Distribution & Density
Published on: Mar 4, 2016
Transcripts - Population Distribution & Density
Population Distribution & Density *Global to local. *Spatial variations with countries at varying stage of development.
Difference between distribution & density <ul><li>Distribution is where people are located in an area. Population distribution is most simply shown on a map by representing each person or group of people by a dot or a symbol. This shows us where people are and gives an impression of how the numbers of people vary from place to place. </li></ul>
Population Density <ul><li>A 2 nd mapping strategy is to plot the distribution of people in terms of the relationship between the numbers and area( people per km ²). The technique widely used to map this it is the choropleth method. </li></ul>
Which mapping method do you prefer & why?
Limitations of Choropleth maps?
Limitations <ul><li>They represent only the average value for each of the units. </li></ul><ul><li>Mean values are generalisation; they conceal spatial variations within the areas they represent. </li></ul><ul><li>When neighbouring spatial units have different densities, the map gives the impression of a sudden break at the boundary. In reality, changes in pop densities are gradual & gentle. </li></ul>
Limitations based on Japan <ul><li>The use of mean density values is flawed. 334 persons per km ² for the whole of Japan understates the actual density of the population. Two thirds of the country is made up of inhospitable mountainous terrain. The settle lowland is not only small, fragmented, but has a very high density +1,000km². </li></ul><ul><li>Better to calculate per unit of habitable space rather than total space. </li></ul>
World Population density 26 35 Oceania 212 736 Europe 839 4,052 Asia 184 577 Latin America & Caribbean 111 338 N.America 205 967 Africa 433 5,479 LEDCs 158 1,227 MEDCs 329 6,705 World Pop density (km ²) Pop 2008 (Millions)
World Population density 49 42 26 35 Oceania 685 726 212 736 Europe 5,427 4,793 839 4,052 Asia 778 687 184 577 Latin America & Caribbean 480 393 111 338 N.America 1,932 1,358 205 967 Africa 8,058 6,731 433 5,479 LEDCs 1,294 1,269 158 1,227 MEDCs 9,352 8,000 329 6,705 World 2050 2025 Projected Population Pop density (km ²) Pop 2008 (Millions)
Why are some areas sparsely populated? <ul><li>Physical – active volcano/mountainous relief. </li></ul><ul><li>Climate – too hot & little rain ( Sahara) or too cold & short growing season (N. Canada) </li></ul><ul><li>Vegetation – Coniferous forests ( N.Eurasia) and the rainforests. </li></ul><ul><li>Soils – Frozen soils – Permafrost (Siberia), thin soils (Nepal), leached soils (Amazon) </li></ul><ul><li>Water supplies </li></ul><ul><li>Disease & pests – malaria Central Africa. </li></ul><ul><li>Resources . </li></ul><ul><li>Communications – Amazon, Sahara. </li></ul><ul><li>Political – Interior of Brazil, where state failed to invest. </li></ul>
Why are some areas densely populated? <ul><li>Physical – flat land and areas surrounding Volcanoes ( Etna). </li></ul><ul><li>Climate – no extremes ( N.Europe) plenty of sun (Costa del Sol) or snow (Alps). </li></ul><ul><li>Vegetation – grasslands. </li></ul><ul><li>Soil – deep, humus filled soil ( Paris) and river deposited silt ( Ganges Delta). </li></ul><ul><li>Water supply – reliable. </li></ul><ul><li>Disease & pests – unlikely or money to eradicate. </li></ul><ul><li>Resources – Ruhr. </li></ul><ul><li>Communications . </li></ul><ul><li>Political – decisions may affect distribution EPZs or New Towns. </li></ul><ul><li>Economic – regions with intensive farming need a large number of people. </li></ul>
Factors affecting the distribution of the population