Population

Mitchell McGovernSarah MasonJessie Fedyke

Importance of Population

• Studying populations allows us to see where people are found across Earth’s surface.

• It also allows us to see the areas where population is growing too fast/ too slow.

• Demography: the study of the characteristics of human populations

• Population is measured by a Census, a count of the number of people in a given area, usually every ten years. Very important to determine government funding.

Declining Rate of Natural Increase• NIR:

-% a population grows each year-CDR-CBR=NIR

• CDR: -Total # of deaths in a year for every 1,000 people

• CBR:-Total # of live births in a year for every 1,000 people

• Doubling Time-# of years needed to double a population

World NIR is decreasing (as of 1963)• Causes:

-Sterilization, especially in India-Increase in Education-Family Planning-Lower birth rates improve economic conditions-propaganda now encourages small families (china)

*Exception: LDC-Almost all the world population growth is from LDC’s (95% of World NIR)

Measures of population• Total Fertility Rate:

-measures the # of births in society, average # of children a woman will have during childbearing years of 15-49.

• World TFR is 2.6 children per woman-LDC’s TFR is high-MDC’s TFR is low

• Infant Mortality Rate-# of deaths of infants under the age of 1, per year-LDC’s IMR is high-MDC’s IMR is low

• Life Expectancy-Average # of years a newborn infant can expect to live at current mortality levels-High in MDC’s-Low in LDC’s

• Dependency ratio-# of people too old or young to work compared to the # of their working years-High levels of YOUNG dependent people in LDc’s -High levels of OLD dependent people in MDC’s

World Population Distribution

• 7 billion• Factors of distribution:

-Climate and Weather, availability/quality of water, topography, arable land, along with political and economic factors

• Culture/ethnicity• Areas of high political instability are undergoing changes

in population • Population growth curves:

-S curve; historical growth-J curve; exponential growth

Population distribution • Ecumene

-Portion of the earth’s surface occupied by permanent settlement-today 3/4ths of the world population lives on only 5% of earth’s surface

• 20% of earth’s surface is not arable due to dry lands and large deserts, low population in these areas

• In areas of high rainfall with more than 50 inches per year the soil is depleted of nutrients therefore the population is low

• Near the North and South poles with massive elevations and ice coverage very little humans or animals live.

Country: PopulationChina 1,354,040,000

India 1,210,193,422

United States 315,761,000

Indonesia 237,641,326

Density• Population Density

-numerical measure of the relationship between the number of people and some other unit expressed as a ratio- helps geographers describe distribution of people in comparison to available resources.

• Arithmetic Density-Total # of objects in an area-To find it you take the total # of people divided by total land area-Does not always accurately portray population distribution because in some countries a large majority of the people live in a certain part, they are not spread out evenly.

• Physiological Density-# of people per area of arable land in a region

• Agricultural Density-ratio of farmers to the amount of arable land-measures economic differences

• Why? -Comparing agricultural and physiological densities allows you to see the relationship between population and resources

World population threats

• Epidemiologic transition: -Focuses on distinctive causes of death in each stage of the demographic transition

• Epidemiology:-branch of medical science concerned with the incidence, distribution, and control of diseases that affect large numbers of people

Epidemiologic transition • Stage 1, Pestilence and Famine ex. Black Plague

-spread from urban areas to rural areas wiping out entire villages, thought to originate from the Tatar army.

• Stage 2, Receding Pandemics occuring over a wide geographic area. ex. -Edwin Chadwick (1800-1890) said that residents in poorer neighborhoods had higher incidences of pandemic diseases -Dr. John Snow (1813-1858) said that the contaminated water was the cause of death, not sinful behavior.

• Stage 3, Degenerative and human-created diseases. Ex. Cancer -End of deaths from infectious illnesses due to vaccines

• Stage 4, delayed degenerative diseases ex. Stage 3 diseases still linger but there are new treatments to extend life expectancy. -Result of more research in medicine and reduced use of drugs.

• Stage 5, Stage of reemergence of infectious diseases and parasitic disease ex. Malaria-Stage is more of a theory, thought to might happen due to evolution with microbes evolving and changing vaccines may stop working, like building up immunity to certain medicine from so much use.

Malthus Theory• Thomas Malthus predicted that population was growing too fast that

eventually we would run out of food.-With an increase in population resources would deplete and disease, famine, and war would ensue. -population grows geometrically while population growths arithmetically

Reasons he was wrong• Malthus failed to anticipate that poor countries would have rapid population

growth • Theory based on his idea that food and resources were at a fixed amount. • Malthus’s arithmetic theory didn’t take into account that too few people could

also slow the economy just as overpopulation might• Food production increased with green revolution

-fertilizer-Genetically enhanced food-technology

Demorgaphic Transition Model• Stage 1: Low Growth, high birth AND death rates

-Hunting and Gathering, no modern medicine, no country is still in stage one today• Stage 2: Death rate drops, but birth rate stays high

-Occurred in MDC’s during the 18th with most LDC’s during mid 19th century due to the industrial revolution, improved sanitation/medicine/technology

• Stage 3:Birth rate drops, death rate low-CBR is still higher than CDR, most MDC’s went through stage 3 during the early 1900’s with a sudden drop of birth rates with rural families moving to cities no longer needing several kids to work farms

• Stage 4: Low growth overall-Countries enter stage 4 when there is zero population growth, or negative growth (communist rule)-BR = DR or zero population growth-most of Europe and the U.S. have zero NIR

• Stage 5: When the crude death rate is higher than the birth rate-no countries have undergone stage 5 yet

Population Pyramids

• Population Pyramid: bar graph that displays age and gender of a population with males on the left and females on right, determined by CBR -broken down into 5 year age groups -Sex ratio: # of males per hundred females

Helpful review links

• http://www.superteachertools.com/jeopardyx/jeopardy-review-game.php?gamefile=1304099801

• http://quizlet.com/18089567/population-and-migration-eghs-human-geography-flash-cards/

• http://www.youtube.com/watch?v=sc4HxPxNrZ0