Population Pyramids and Population Density Maps

Population Two useful ways that geographers can graphically display population information include: Population Maps to depict population density Population Pyramids to depict population distribution

Population Density… …is a measure of how many people live in a certain unit area Take the population of a region and divide it by its square area Ex.: The population density of Texas is 79.6/mi² On average, 79.6 people live in a square mile in Texas

One type of population map shows one dot for every certain number of people who live in a place:

Another type shows population as color coded regions:

Population Pyramids A population pyramid is a bar graph, usually in the shape of a pyramid, used to compare different age groups of men and women.

Population Pyramids These graphs show how a population is distributed between age groups and sexes by percentages or numbers.

Lower age groups are at the bottom Men are left of center Women are right of center

In this pop. pyramid, the majority of the population is young, because there is a high birth rate and a high death rate

India, year 2000: large young population, high birth rate, high death rate

India, year 2025: death rate decreases, the younger population grows older

India, year 2050: the population has bulged in the age groups

China:

South Korea’s Population Boom

The Aging of Japan Low Death Rate and Dropping Birth Rate

Triangle Developing Rapid Growth

Box Developed Slow Growth

Modified box, glass or cup Higly Developed Negative Growth

Population Growth Theories Malthusian Theory In 1798 Thomas Malthus published his theory The population will continue to grow until it surpasses the food supply People will starve reducing the population back to a sustainable level

Neo-Malthusian Theory The population is growing faster than Malthusian anticipated Beyond the capacity of food and: Clean air Living space Fuel

According to these theories, a catastrophe is imminent to reset the population World population since 500 A.D. Evidence: Starvation in Africa Loss of farmland in China, South America, and Africa Natural disasters worldwide

What do you think is going on in each U.S. city? Write down your guesses in your important books.