Transcript Chapter One
An Introduction to Human Geography The Cultural Landscape, 9e James M. Rubenstein Chapter 2 Population Victoria Alapo, Instructor Geog 1050 Distribution of World Population • Population concentrations – The four largest population clusters (see text). Pg 47-49. – Other population clusters • Sparsely populated regions – Dry lands – Wet lands – Cold lands – Highlands • Population density (discussed later) – Arithmetic density – Physiological density/ Agricultural density World Population Cartogram This cartogram displays countries by the size of their population rather than their land area. (Only countries with 50 million or more people are named.) Pg 47 World Population Distribution World population is very unevenly distributed across the Earth’s surface and it can be compared to climate distribution. Arithmetic Population Density Arithmetic population density is the number of people per total land area or per square mile/km. The highest densities are found in parts of Asia and Europe. Physiological Density Physiological density is the number of people per arable land area. This is a good measure of the relation between population and agricultural resources in a society. Crude Birth Rates The crude birth rate (CBR) is the total number of births in a country per 1,000 population per year. The lowest rates are in Europe, and the highest rates are in Africa and several Asian countries. Crude Death Rates The crude death rate (CDR) is the total number of deaths in a country per 1,000 population per year. Because wealthy countries are in a late stage of the demographic transition, they often have a higher CDR than poorer countries – more older people than younger people. Natural Increase Rates The natural increase rate is the percentage growth or decline in the population of a country per year (not including net migration). i.e. natural increase or decrease is the difference btw birth and deaths. Countries in Africa and Southwest Asia have the highest current rates, while Russia and some European countries have negative rates. Total Fertility Rates The Total fertility rate (TFR) is the number of children an average woman in a society will have through her childbearing years. The lowest rates are in Europe, and the highest are in Africa and parts of the Middle East, due mainly to Social Reasons. In traditional societies, CHILDREN take care of their parents, not Social Security. Infant Mortality Rates The infant mortality rate is the number of infant deaths per 1,000 live births per year. The highest infant mortality rates are found in some of the poorest countries of Africa and Asia. Life Expectancy at Birth Life expectancy at birth is the average number of years a newborn infant can expect to live. The highest life expectancies are generally in the wealthiest countries, and the lowest in the poorest countries. Variations in Population Growth • The Demographic Transition Stages – 1. Low growth – 2. High growth – 3. Moderate growth – 4. Low growth • Countries are in different stages of demographic transition, which can be shown with the aid of “population pyramids”. • Population pyramids – Shows age distribution & gender ratio (see slides) The Demographic Transition The demographic transition consists of four stages. See text, pg 58, Fig 2-13. Population growth is most rapid in the second stage. Population Pyramids – This is a graphic device showing the age and sex structure of a population. See pyramid showing “high growth” (below). Population Pyramids • Pyramids also help to show the “dependency ratio”: – Which calculates the proportion of the population of working age to the non-working age. See pyramids. – The dep. ratio is when you compare the ratio of the combined pop. of children less than 15 yrs and elderly over 64, to the pop. of those btw 15 & 64 yrs (working age). – The larger the % of dependents, the greater the dependency ratio and financial burden – rich countries have too many old; poor countries have too many young (see slides). Population Pyramids in U.S. Cities Population pyramids can vary greatly, with different fertility rates (Laredo vs. Honolulu), or among military bases (Unalaska), college towns (Lawrence), and retirement communities (Naples). See textbook. Will the World Face an Overpopulation Problem? • Thomas Malthus on overpopulation – His theory on population growth and food supply (geometric vs. arithmetic progression) – Malthus’ critics: the “Cornucopians” • Declining birth rates – Malthus theory and reality – Reasons for declining birth rates Food and Population, 1950–2000 Malthus vs. Actual Trends Malthus predicted population would grow faster than food production, but food production actually expanded faster than population in the second half of the twentieth century. Why? Food Supplies Over the Last 200 Years (Affected Malthus’ Prediction) • Malthus’ prediction • Technological advances: • Green revolution • New crops – Transplants and genetic engineering • New cropland – New lands opened by irrigation • Transportation and storage – Faster refrigerated modern methods – Improved storage protects against spoilage and pests