Standard 9: CHARACTERISTICS, DISTRIBUTION, AND MIGRATION OF HUMAN POPULATION Human population has increased dramatically over the last few centuries. By the late 1980s, Earth’s population had reached 5 billion, and by 1999, it surpassed 6 billion.

World Population Clusters There are several At the same time, extraordinarily large and dense clusters of people are growing: Tokyo has already reached a population in excess of 25 million. Other densely populated clusters are: Eastern China; India; Indonesia; Western Europe; the Eastern Seaboard of the US; Valley of Mexico; Western Africa

CHARACTERISTICS, DISTRIBUTION, AND MIGRATION OF HUMAN POPULATION

One of the major themes in geography is ‘human-environment interaction’. That is, how do various populations interact with the environment in which they dwell?

More Factors Examined in Population Studies Apart from knowing how many and where people are on the planet, population studies also examines birth rates and death rates in a given population, fertility rates, mortality rates, life expectancy, and sex/gender distribution in a place/region. An increased awareness of both the physical and social factors that affect population, helps geography teachers and students understand how and why and where there are very dense or sparse population, how fast a given population is growing (population growth rate) and also helps us make informed projections of future growth rates in a given place. An excellent tool for interpreting some basic characteristics is a ‘population age- structure diagram’ or ‘population pyramid’. For example: age and gender distribution of a population; life expectancies; percentage of a population in 5-year age cohorts; and population growth and decline (for any number of reasons). We will examine examples of several age-structure diagrams next.

Progression of Population Growth in the US –

Population of Maryland: 1950 &1980; and 2010 & 2030 (projected) Age/Gender Population for Maryland – 1950 – in 5-year age cohorts Age/Gender Population for Maryland – 1970 Age/Gender Population for Maryland – 2010 Age/Gender Population for Maryland – 2020 These population pyramids show a progression of population by age/gender distribution in the State of Maryland’s Age between 1950 and 2020.

Following the Baby Boom Generation in the US (born: ) 2005

Selected Demographic Statistics for Three Countries in Three Stages of Economic Development

Urbanization & Population

The red arrow represents migration from 1955 to 1960, and the blue arrow represents migration from 1995 to Migration between California and Other States, 1955 to 1960 and 1995 to 2000

The purple arrow represents migration from California, the orange arrow represents migration from New York, and the blue arrow represents migration from Texas. Outmigration of the Foreign Born, 1995 to 2000: California, New York and Texas.

How “Population Shifts” (increases or decreases) Affect Nature & Society Demographic shifts rearrange patterns of population and create new human landscapes –Natural increase, war, famine, and disease play decisive roles in influencing why many people live where they do –Migration sets people in motion as they leave one place, move to a second, and possibly settle in a third Intervening obstacles influence the pattern of migration –Physical barriers such as deserts, mountains, rivers, and seas or cultural barriers such as political boundaries, languages, economic conditions, and cultural traditions determine how people move and where they settle.

By Elizabeth Larson, PhD Lecturer, School of Geographical Sciences and Urban Planning, Arizona State University, 2010