The first ever census of population was held in
the USA in 1790
The first census of the UK was held in 1801.
Sri Lanka held its 1st census in 1871.
There are 4 stages in the growth of a population.
Stage 1:
o High death and birth
rates
o Population growth is
low
o Time taken to double
the pop. Is long
Stage 2:
o High birth rates
o Death rate shows a
steady decline
o Population growth is
increasing
o Time taken to double
the population decreases
Stage 3:
o Death rate remains
low
o Birth rate too is
declining
o Decrease in
population growth
o Time taken to double
the population increases
Stage 4:
o Death and birth
rates are low
o Rate of population
growth is low
o Time taken to double
the population increases
Developed countries are in stage 4 of this graph. Sri
Lanka too has reached stage 4 despite being a developing country.
Distribution of Population – World
Regions
of high population density:
o South and SE Asia
o Eastern Asia
o Western Europe
o NE America
Physical
factors related to population density in some areas:
o Relief and drainage
o Presence of natural
resources
o Economic activities
o Infrastructure and
services
o Pleasant climate
o Historical factors
Reasons
for low population density in some areas:
o Harsh conditions –
too hot/ too cold – Sahara, Arabian Peninsula, Alaska, Siberia, Antarctica
o Shortage of water
o Rough terrain and
relief – Alps, Himalayas, Andes
o Dense forests –
Congo, Amazon
Factors
affecting changes in population:
- Births – death = Natural Growth
- Arrivals – departures = Net Migration
- (Births - deaths) + Net migrations = Population growth
In
the period between 1871- 1946 the main reason for population growth was
Migration.
The
main reason for population growth after 1946 has been Natural Growth.
Population of Sri Lanka
Total
land area of SL is 65,525 sq. km
According
to 2001 census the population of SL is 18,732, 250
Therefore,
the density of population is 299 per sq. km
District
Colombo
Gampaha
Kaluthara
A’
pura
Polonnaruwa
Monaragala
Sq. km
3305
1541
673
112
117
72
Highest
population density
: Colombo,Gampaha, Kalutara, Kandy
Lowest
population density : Monaragala, Miallaitivu
Composition
of a population could be categorized according to:
o Race
o Religion
o Gender
o Age
o As urban/ rural/
estate
Structure of population
|
Age
|
1981
|
1991
|
2001
|
|
Below
14 (child dependents)
|
35.2
|
31.2
|
25.7
|
|
15
–64 (labour force)
|
60.5
|
63.4
|
67.6
|
|
Above
64 (adult dependents)
|
4.3
|
5.4
|
6.7
|
|
Total
dependents
|
65.2
|
57.7
|
47.9
|
According
to the above table
- Percentage of the young dependents is decreasing
- Percentage of adult dependents is increasing
- The labour force is increasing, therefore, the no. of dependents is decreasing.
Yet the figure of dependents is misleading as it
also includes:
o People who are
engaged in full time studies
o People who are
unemployed
o Women who are
employed as house maids
o Pensioners
As a result of the increase in population the
socio- economic climate of the developing countries is becoming poorer.
Resources that should be spent on development work have to be spent on food,
clothes, housing and health facilities for the ever-increasing population.
Though
the population keeps on increasing at an alarming rate the land and most of the
resources do not increase.
Only
30% of the total landmass is suitable for any meaningful form of agricultural
activities.
Problems
related to over population:
- Housing
- Employment
- Drinking water
- Shanties
- Epidemics
- Urbanization
- Garbage disposal and sanitary facilities
- Energy requirements
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