Class 12 Geography Notes Chapter 2 The World Population is a Part of NCERT Book Of Class 12 CBSE Board For really Quick revision . Here sidclasses.in Provides you the best notes for Chapter 2 The World Population so you can score really good marks in your CBSE Board Exams
Geography Class 12 Notes Chapter 2 The World Population
The Pattern of Population Distribution-
- Population distribution means arrangement distribution of people over the earth’s surface. Population is not evenly distributed as 90 percent of the world’s population lives in about 10 percent of its land area.
- The 10 most populous countries of the world contribute about 60 per cent of the world’s population. Out of these 10 countries, 6 are located in Asia.
What is Population Density ?
- This means the ratio between the number of people to the size of the land. It is usually measured in persons per sq km density of population/area. Some areas are densely populated like North-Eastern USA, North-Western Europe, South, South-West and East Asia.
Measured in persons per SQ. km Density = Population/area
• High Density Areas: (more than 200 persons/sq km) NE USA, NW Europe, S, SE, and E Asia
• Low Density Areas (less the 1 person / sq km) hot and cold deserts, low latitude areas
• Medium Density: (11-50 persons /sq.km) other than above two areas.
Factors that influence the distribution of population
• Geographical Factors
(a) Availability of water,
(b) land forms,
• Economic Factors
• Social and Cultural Factors
(a) Religious factors,
(b) social and political unrest,
(c) border terrorism,
(d) govt. policies
Population Growth: Change in number of persons of a place during a specific period of time it may be positive or negative. It may be represented in absolute numbers /percentage Change in population.
Basic Concepts Are:
• Growth of population,
• Growth rate of population,
• Natural growth of population,
• Positive growth of population
• Negative growth of population.
Components of Population Change
There are three components of population change i.e., births, deaths and migration.
Crude Birth Rate [CBR]
Number of births in a year per thousand of population is expressed as Crude Birth Rate (CBR). It is calculated as:
Here, Bi= live Births during the year; P = Mid year population of the area.
Crude Death Rate (CDR)
Number of deaths in a year per thousand of population is expressed as Crude Death Rate (CDR). It is calculated as:
Here, D= Number of Deaths; P= Estimated mid-year population of that year.
It is movement of people across region on permanent, temporary or seasonal basis. The place they move is called place of origin and the place they move to is called place of destination.
Trends in Population Growth
- Trends show that initially growth of population was very slow but after the improvement in Science and Technology, there had been tremendous growth in population which is called population explosion.
- About 8000 to 12000 years ago world population was 8 million and now it has reached to 7 billion.
- In every 12 years, 1 billion people are added. Increased agriculture and industrial production, inoculation against epidemics, improvement in medical facilities have reduced death rates.
Doubling Time of World Population
- Developed countries are taking more time to double their population as compared to developing countries.
- Oman, Saudi Arabia, Somalia, Liberia, Yemen have high population growth rates while Latvia, Estonia, Russia, Germany, etc have low growth rates.
Spatial Pattern of Population Change
- The world population growth rate is 1.4%, it is highest in Africa i.e. 2.6% and lowest in Europe i.e. 0.0% means neither grow nor decline.
- So even when a small annual rate is applied to very large population, it will lead to a large population change. There is negative correlation between economic development and population growth.