POPULATION PYRAMIDS Pictorial presentation of 3 Factors (Influence Population) Births Deaths Migration
Features (Population Pyramids)In terms of its composition by:- Age, Sex Males (on Left side) Females (on Right side) Children (at bottom) Elders (at Top) Adjoining bars(contribution of each age, Sex group)
EXAMPLE Developing DevelopedCountry Countries (Pakistan) (Sweden) Base: Narrow (Low BirthBase: Broad (High Birth rate)rate) Middle: Bulge (Convex border)Top: Narrow / Acute apex Top: Obtuse apex (No: of Elders (Less) (More Elders) Low Dependency rateHigh Dependency rate Good effect (on Economy) Bad effect (on Economy) Productive ( More than Half Unproductive (Half Pop)Pop) Under 15 Ys: ---- 25% Pop: Under 15 Ys: ---- 44% Above 15 Ys: ---- 75% Pop:
DEMOGRAPHICCHARACTERISTICSPopulation unevenly distributed with very densely populated very sparsely populated areas areas. All countries in region have a positive rate of natural population change.
DEMOGRAPHIC TRANSITIONTwo demographic worldsLess-developed counties represent 80% of the world population, but more than 90% ofprojected growthRicher countries tend to have negative growth rates. Growth Rate (%) Grading of population increase 0 ( Zero) Stationary Growth (No Growth) 0 to 0.5 Slow Growth 0.5 to 1 Moderate Growth 1 to 1.5 Rapid Growth 1.5 to 2.0 Very Rapid Growth >2 Explosive Growth ( Population explosion) OR Population Bomb
DEMOGRAPHICTRANSITION 3 TYPES1. Old balance Fertility Mortality2. New balance Fertility Mortality3. ImbalanceFertility Mortality
DEMOGRAPHIC CYCLE Population Grows rapidly Germany, Hungary (after effect of India in II world war) Population 1920-1930 Population Becomes Population Grows stationary Population declines slowly stationary Many countries China, of S. Asia & Singapur Africa Pak in 1970
Demographic Transition Accompanying Economic and Social Development B Birth Rate Death Rate15
Note that in English, fertility refers to actual births. Fecundity refers to the biological ability to have children (the opposite of sterility).
Dependency Ratio The dependency ratio tells us how many young people (under 16) and older people (over 64) depend on people of working age (16 to 64). The dependency ratio is worked out with this formula. Dependency Ratio = % under 15 + % over 65 ys: X 100 % between 15 & 64 A worked example should make this clearer. Pakistan, which is a developing country, has 41% of its population less than 15, and 4% over 65. This makes 55% (100 - (41+4)) between the ages of 15 and 64. Dependency Ratio = 41 + 4 X 100 = 81.8 55