demography
the scientific study of population characteristics
overpopulation
the number of people in an area exceeds the capacity of the environment to support at a decent standard of living
ecumene
the portion of Earth's surface occupied by permanent human settlement
arithmetic density
the total number of people divided by total land area
physiological density
the number of people supported by a unit area of arable land
agricultural density
the ratio of the number of farmers to the amount of arable land
crude birth rate
the total number of live births in a year for every 1,000 people alive in the society
crude death rate
the total number of deaths in a year for every 1,000 people alive in the society
natural increase rate
the percentage by which a population grows in a year
doubling time
the number of years needed to double a population
total fertility rate
used by geographers to measure the number of births in a society
infant mortality rate
the annual number of deaths of infants under one year of age
life expectancy
measures the average number years a newborn infant can expect to live at current mortality levels
demographic transition
the process of chance in a society's population from a condition of high crude birth and death rates and low rate of natural increase to a condition of low crude birth and death rates, low rates of natural increase, and a higher total population
agricultural revolution
the time when human beings first domesticated plants and animals and no longer relied entirely on hunting and gathering
Industrial Revolution
a series of improvements in industrial technology that transformed the process of manufacturing goods
medical revolution
improved medical practices have eliminated many of the traditional causes of death in poorer countries and enabled more people to live longer and healthier lives
zero population growth
a decline of the total fertility rate to the point where the natural increase rate equals zero
dependency ratio
the number of people who are too young or too old to work
population pyramid
a country's population can be displayed by age and gender groups on a bar graph
sex ratio
the number of males per hundred females in the population
census
the single most important data source for human geographers
epidemiologic transition
distinctive causes of death in each stage of the demographic transition
epidemiology
the branch of medical science concerned with the incidence, distribution, and control of diseases that affect large numbers of people
pandemic
disease that occurs over a wide geographic area and affects a very high proportion of the population