1. POPULATION GROWTH
Specifically, population growth rate refers to the change in population over a unit time period, often expressed as a percentage of the number of individuals in the population at the beginning of that period.

3. In the last two centuries ,FOUR DEVELOPMENTS have occurred that created environmental problems beyond natures assimilative capacity
There has been an EXPLOSIVE GROWTH OF POPULATION, creating enormous environmental pressures because of sheer numbers of people on earth.
2 . This growth, particularly in the developed countries has been accompanied by NEW INDUSTRIAL PROCESSES
whose wastes have caused environmental damage.
Population growth and industrialization have given RISE TO URBANIZATION – movement of people from small settlements to cities and town-thus increasing local environmental problems, because of the high density of people and industry.
finally the EXPLOSIVE GROWTH OF ENERGY USE and the introduction of many new products, particularly
since world war-II, have added more environmental stress.

4. POPULATION GROWTH

5. POPULATION GROWTH
There are 3 MAIN FACTORS responsible for changes in population
Births 2. Deaths 3. Migrations
The present and past population record for the city can be obtained from the census
population records. After collecting these population figures, the population at the end of
design period is predicted using various methods as suitable for that city considering the
growth pattern followed by the city.
Population forecasting is done by mathematical formulae and graphical solutions based upon previous population records
1. ARITHMETICAL INCREASE METHOD 2. GEOMETRICAL INCREASE METHOD 3. INCREMENTAL INCREASE METHOD 4. GRAPHICAL METHOD 5. COMPARATIVE GRAPHICAL METHOD 6. MASTER PLAN METHOD 7. CURVE METHOD

6. ARITHMETICAL INCREASE METHOD
This method is suitable for large and old city with considerable development. If it is used for small, average or comparatively new cities, it will give low result than actual value. In this method the average increase in population per decade is calculated from the past census reports. This increase is added to the present population to find out the population of the next decade. Thus, it is assumed that the population is increasing at constant rate.
Therefore, Population after n th decade will be ;
Pn= P + n.C
Where,
dP/dt = C i.e. rate of change of population with respect to time is constant
Pn = is the population after n decade and
P = is present population.
n= period of ten years

8. GEOMETRICAL INCREASE METHOD (OR GEOMETRICAL PROGRESSION METHOD)
In this method the percentage increase in population from decade to decade is assumed to remain constant. Geometric mean increase is used to find out the future increment in population. Since this method gives higher values and hence should be applied for a new industrial town at the beginning of development for only few decades.
The population at the end of nth decade ‘Pn’ can be estimated as:
Pn = P (1+ IG/100) n
Where,
IG = geometric mean (%)
P = Present population
n = no. of decades.

10. INCREMENTAL INCREASE METHOD
This method is modification of arithmetical increase method and it is suitable for an average size town under normal condition where the growth rate is found to be in increasing order. While adopting this method the increase in increment is considered for calculating future population. The incremental increase is determined for each decade from the past population and the average value is added to the present population along with the average rate of increase.
Hence, population after nth decade is
Pn = P+ n.X + {n (n+1)/2}.Y
Where,
Pn = Population after nth decade
X = Average increase
Y = Incremental increase

12. HOME WORK

13. INDUSTRIALIZATION
For most people ,the word Industrialization is connected historically to the Industrial Revolution of the 80th and 90th centuries, with its origin in Great Britain. It was distinguished by numerous technological inventions, including ,most notably ,the spinning jenny and the stem engine.
the ultimate benefit of the Industrial Revolution for the individual was a higher standard of living through higher wages.

14. URBANIZATION
Economic growth related with Industrialization which means Urbanization
there have different definitions of Urbanization. Some country distinguish between URBAN and RURAL by size of the community.
Expl.
1. areas with as few a 400 inhabitants are designed as urban in Albania
2. In Japan Lower Limit is 50,000 inhabitants.
3. some countries ,urban status assigned on the basis of density.
a. In Sweden those built- up areas with less than 200m between houses
b. In India ,places having a density of not less than 1000persons/sq. km where at least ¾ of the male adult population is employed in non-agricultural work are called urban.