Chapter 3
CHAPTER NO.3 IMPACT OF HUMAN ACTIVITIES
ON ENVIRONMENT
During the 20* century, especially during the last
two decades, science and technology have made an overall progress and advancement
in many areas. On one hand, this advancement has given
many comforts to man on the other hand, the progress
made is proving counter productive in certain ways. Say for instance, this
advancement has disrupted the fragile woven web of life, besides affect-ing the
enviromnent in a number of ways. Various human activities have been found to
have varied impact on the environment, as evident from the following:
Environmental problems of urban and rural areas
Natural resources and their depletion
Stress on civic amenities
Vehioul .
Urbanisation
ENVIRONMENTAL PROBLEMS OF URBAN AND
RURAL AREAS
The human society may be urban society, living in
cities and towns or rural society, living in villages. Both the societies have
their own environmental interaction and problems.
Urban problems: The environmental problems of the
urban areas are more serious than those of rural areas. This is an outcome of
the modern consumerist culture i.e. industralization and overcrowding. As the
urban population grows, it adds strain to the supporting system of the
environment, foremost of which is the pollution. It is found in the air we
breathe, the water we drink, the food we eat and the sound we hear. In order to
make it more clear, same
specific problems can be referred to as follows:
The growing population puts a lot of pressure on
limited land in different cities. Also to expand the urban areas, large scale
deforestation is being done. It along with buming of the fossil fuel is
resulting in global warming. As the cost of the land rises, the poor people
cannot afford land to construct their houses and as
a result slums start developing around all major cities
(Fig 3.1).
Slums are unorganised and densely polulated areas
having poor standard of living conditions and open sewage system. The slums
have open sew-
age system and become most unhygienic places around
urban areas. The urban areas with growing population produce a lot of solid
waste. Many environmental problems are created due to shortage of dumping sites
for appropriate disposal. As the waste piles up, it reaches into water bodies
and becomes a cause of many water borne diseases.These wastes also emit very
foul smell. Besides they beecome breeding grounds for rodents and insects.
Generally, these wastes are dumped into near by rivers or lakes that
affect the aquatic flora and fauna (Fig. 3.2).
Polluted air is another problem of the urban areas
due to industries and vehicular emis-sion. Continuous inhaling of such air
causes many respiratory problems. In winter months,due to low temperature the
industrial smoke gets converted into smog. It is very harmful
to eyes and lung. It also lowers the availability of
sunlight. The burning of fossil fuels also produces sulphur dioxide. It
combines with water vapours present in the atmosphere to form sulphuric acid.
It becomes the cause of acid rain that affects our life in different ways.
The growing urban population creates an acute
shortage of water and electricity. In summer month, people use generators to
get continuous supply of electricity. The smoke and sound produced by these
generators cause air and noise pollution respectively.
High cost of eatables, entertainment, education and
medical facilties have also become a problem for urban people.
Rural problems: As far as, the environment is
concemed, rural problems are comparatively less as compared to urban problems.
The major rural problems are due to non availability or
poor availability of services like education and
medical facilities. In certain villages, there are no schools and the children
have to go to nearby cities or towns for their education. The
institutes for higher education are totally absent
in many rural areas, thus most of the students,especially the girls do not go
for higher studies. Some of those who go to the cities have to
face financial problems due to high cost of living
there. Similarly, in most of the villages, there are no hospitals or
dispensaries, If at all these are present, they are ill equipped. They have to
tun to the cities for even minor ailments. The rural people have to depend upon
hand pumps,ponds and wells to fulfill their water needs. The animals and
washing of clothes in ponds
pollute these water bodies. The pond water becomes a
breeding ground of many insects particularly the mosquitoes. Open lavatory
system, unhygienic sanitary conditions and im-proper drainage system also
aggravate the environmental problems. In many villagers, facili-ties such as
post office, telephone and baking are lacking.
In rural areas, the excessive use of chemical
fertilizers, insecticides, weedicides and other pesticides for agricultural
purposes pollute the wate bodies (Fig 3.3). When used for drinking
purposes, this water may become a cause of many
serious diseases like cancer, etc. The excessive use of these chemicals have
also resulted in the loss of biodiversity.
NATURAL RESOURCES AND THEIR DEPLETION
Natural resources conists of energy and matter
obtained from the environment for the use of living organisms, including man.
These resources can be classified as renewable and non-renewable.The renewable
resources ate those which can be replenished by the natural processes. These
include soil, air, water, plants and animals. The non-renewable resources such
as coal, iron ore, petroleum
etc. cannot be replenished. There are four major
causes of depletion, as follows:
(1) Population growth
(2) Over use of resources
(3) Non equitable distribution of resources
(4) New technological developments
(1) Population growth :
There was a little depletion of natural resources when human popula-tion was
small. As the population explosion took place in the 20th century, the demand
for food, minerals, wood and other commodities increased. Forests were rapidly
cut to get more food and woods bringing. To get more minerals for industries,
the mines are overused and this destroys the ecosystem, To create more houses,
new colonies and cities, the resources
are used indiscriminately. Thus population growth
leads to pollution, crowding, destruction of habitat and exhaustion of natural
resources.
(2) Over use of resources:
The growth in population is the main cause of overuse of natural resources like
soil, water, minerals and forests.
Soil : The soil supports all living organisms. The
plants get their water and nutrients supply from the soil. The animals,
including man get their food directly or indirectly from.the soil. It also
provides fibre, wood and many other products. Due to growing popula-tion, the
soil is overused to grow more and more food. Though, soil is a renewable
source, yet it needs time to replenish itself after
every harvesting of a crop. But due to lust to grow more crops, many farmers do
not keep the soil free even for few weeks after harvesting wheat. Say for
instance, after harvesting wheat, they immediately sow a
sathi variety of rice, followed by the regular
variety of rice. It leads to greater loss of nutrients from the soil. It is
being compensated by adding chemical fertilizers. But these
fertilizers pollute both the soil and the water
sources. Excessive use of pesticides also affects the soil adversely.
Monoculture i.e., growing same crop every time also effects
the fertility of the soil. Besides these factors,
the soil is also degraded by over grazing and erosion caused by water and wind.
(ii) Water : Water is another important element in
the biosphere and is essential for exist-ence of all forms of life on the
earth. All human activities and economic developments depend upon water
directly or indirectly. It is a divine drink essential for sustaining life.Though,
the planet earth is known to have 97% of water in oceans, yet it is of very
little use to man due to salinity. The ground water is the main source of water
for man,besides fresh water from rivers and lakes. The water is mainly consumed
by human population and in agriculture and industries. It has been estimated
that all over the world 65%, 25% and 5% water is used in agriculture, industry
and domestic purposes respec-tively. The growing population and other fast
developments lead to an overuse of wafer.
Underground water is considered to be a better
natural resource. It gets recharged.naturally by seepage from the surface as
well as from underground water flows. It,however, needs some time to replenish
the underground water. The excessive use of water for irrigation is considered
to be main reason of water depletion. The other main factor for water depletion
is its injudicious use by millions of people living in large cities.The surface
water is also over used and contaminated by farm practices, industries and even
by domestic wastes.
The population explosion has led to more extensive
and larger network of dams and
reservoirs. There are more than 36,000 dams in the
world. This network regulates the water supply throughout the year. But it reduces
the total flow because of loss through evaporation over larger surface area of
such reservoirs. No doubt the dams provide electricity, help in controlling
floods, provide irrigational facilities, but their adverse impact on the
vegetation cover and the ecosystem cannot be ignored.
The ocean water is not used directly by man but it
is a highly productive source of about 130 billion tonnes of food in the form
of fishes, prawns, whales and other seafoods. In this respect also, the over
use of marine food has lead to its depletion.
(ili) Minerals:
The Minerals come under non-renewable resources of the environment. It means
that once they are depleted they cannot be replenished. Like other
resources,due to an increase in population and industrialization, the per
capita demand for energy is increased. To meet this demand, the fossil fuels
are being over used. Similarly, miner-als like manganese, copper, tin and zinc
are extensively used to meet the urban needs.For example, on an average, each
citizen uses 25kg of aluminimum, 550kg of iron and 10kg of copper per year in
the United States. In cities where lot of new construction is going on,
requires huge amount of cement, bricks, limestone, marble, slate granite etc.
Oceans are well known reserves of many minerals like
gold and petroleum. According to an estimate, ocean has about 1,250 billion
barrels of petroleum and 10 billion tones of gold. By the year 1960, 100
billion barrels of petroleum has already been extracted.
Thus it is evident that if an over exploitation of
these resources continues at the present rate, they will exhaust in few
decades.
Forests: Forests are vital for our environment. They
play an important role in maintain-ing global ecosystem at various levels. The
important functions of the forests are: the supply of timber for housing, wood
for fuel, raw materials for the forest based industries,prevention of soil
erosion and preservation of watersheds. The forests prevent siltation of the
dams. They also maintain earth's temperature. Above all, forests provide
habitat
for rare plants and ani-mals.
The forests are being destroyed. indiscrimi-ig 3.4).
In India alone,
22 million hectare for-ests have been de-stroyed
during the last three decades. The de- forestation will lead to soil erosion,
recurrent flooding, loss of rare animal and plant species, besides significant
changes in the climate. All such changes will put a serious impact on human
health and economy.
3) Non equitable distribution of
resources: The natural resources are not uniformly
distrib-uted and thus there are many problems in their utilization. For
example, Mesabi range of the
USA is tich in iron ore reserves and an
over-utilization of these reserves resulted into closure of many mines. On the
other hand, due to rough and harsh climatic conditions of Eastern part
of Russia, its mines rich in tin and gold remain
unutilized.
Unequal distribution of resources increases the cost
of production, as the industries have to trensport raw material from long
distance. For instance, Japan is an highly industrialized country of the world
but it has no raw material of its own and thus they have to import raw
materials
from other countries.
Unequal distribution is a cause of many disputes
amongst different states of India and also between many countries. The Satluj
Yamuna Link canal has created dispute between Punjab and Haryana. Similarly,
Cauvery rivers is a dispute between Kerala and Tamilnadu. At interna-tional
level, there is a dispute of Mekong river that passes through China, Myanmar,
Laos,Thailand, Cambodia and Vietnam.
(4) New technological developments: As per
anthropological records, the earliest human so-ciety consisted of hunters and
gatherers. The first great revolution took place during stone
age, when man started agriculture along with
domestication of animals. It was most suitable because of less population and
limited needs of the man at that time. It provided a some sort
of stable ecosystem to that society. As the
population started increasing, the then agricultural practices could not meet
its requirements and the second great revolution took place. An
industrial revolution started in 18th century in
England. The raw material for the industries was mainly the minerals or
agricultural products. Since then, to meet the demands of indus-tries both
these resources have been overn uitlized.
The present age is the age of technology. It invents
new, fast and efficient methods for the industry. The most significant of these
technologies are nanotechnology, biotechnology and
bioinformatics etc. These technologies are expected
to be of great use in treating most dan-gerous diseases, inventing alternative
soures of energy, cheap and protein rich foods etc.
STRESS ON CIVIC AMENITIES
According to Oxford Dictionary, the term ‘civic’ is
connected with city or town and the term ‘amenity’ refers to the features that
make a place pleasant or easy to live in. Thus in composite way,
civic amentities refer to the facilities provided by
civic achministrative to the peoples dwelling in citiesand towns to make their
life comfortable. Such facilities include clean drinking water, regular supply
of electricity, transportation, medical facilities and disposal of wastes.
(1) Clean drinking water:
The supply of clean drinking water is the foremost responsibility of civic
administration because most of the disease are directly or indirectly related
to water.
According to an estimate, 25 million people die
every year from disease caused by unsafe drinking water in the developing
countries. About 30% of people do not have access to safe
drinking water. In many rural areas, women and
children have to spend many hours a day to fetch water to fulfill their daily
needs. In big cities, due to increasig population and excessive
use of water, there is generally a shortage of clean
drinking water, especially during summer months. During the rainy season, the
contamination of water takes place in certain areas
having faulty infrastructure and that poses serious
health problems,
(2) Regular supply of electricity :
Electricity is another basic amenity, especially of the present generation.
Most of the electricity is used by industries and farms and there is mostly a
shortage of electricity for the domestic purposes. In summer season, this
problem becomes more acute due to the use of air conditioners. Due to non
availability of electricity, people use
generators that become a cause of noise and air
pollution.
3) Transportation :
In big cities, people have to travel long distance for attending their
duties.In most of the cities, there is no efficient public transport system and
as a result there is a traffic jam during the peak hours. The poor quality of
public transport causes lot of air and noise pollution. Even within over
crowded cities cars, scooters, three wheelers intenmingle
with bicycles, rickshaws and pedestrains and result
in frequent traffic jams.
(4) Medical facilities:
The health of a nation depends upon its healthy inhabitants. Increase in the
volume and growth of human population put a pressure on existing hospitals and
health centres. From time to time the civic administration has to open new
hospitals, besides up-grading the existing ones to meet the ever increasing
demands of the people.
(5) Disposal of waste:
Wastes are the products which are no apparent use. Such wastes are produced by
human beings, agriculture and industries. Each Indian individual generates
250-300 gm of waste per day. Mumbai is the largest waste generator of India
which produces
about 5000 tons of waste per day. Thus, it has become
the foremost duty of the civic administration to dispose of the waste through
safe methods. Disposal of the liquid waste or sewage is more difficult,
especially during rainy season. The disposal of wastes in cities pre-sents a
grim picture.
Tn some cities the wastes are thrown into rivers. It
is estimated that about 900 million litres of sewerage and industrial wastes
enter the sacred Ganges river every day. Defecation along the banks of river is
another common practice followed by the people living in slums of big cities.
VEHICULAR EMISSION
It includes the pollutants added into the
environment by automobiles aircraft etc. Automobile exhaust contains unburnt
hydrocarbons which produce photo-chemically active formaldehydes re-
sponsible for irritation in the eyes. The main
source of carbon monoxide in the environment is the automobiles. When inhaled
by man, carbon monoxide canse many respiratory problems. The emis-
sion also contains catbon, sulphur and nitrogen.
Their reaction with each other in the presence of ultraviolet sunlight is very
harmful. The nitrogen oxides of the emission react with particulate present in
the air in the presence of sunlight and produce smog. Smog becomes a general
phenomenon in big cities during winter. It reduces visibility that becomes the
cause of accidents. It also causes itritation in eyes, throat and lungs. The
emission is also very rich in carbon dioxide which creates green house effect
in the environment. It is responsible for global warming.
URBANISATION
It is the process by which large numbers of people
get permanently settled in cities. As per census of 1961 and 1971, the urban
area is defined as the area that include
Thearea having a minimum population of 5000.
Itshould have notified area committee, or cantonment,
or municipality or a corporation.
Its population density is more than 1000 persons per
square kilometer.
Atleast 70% of male population is employed in jobs,
other than agriculture.
The combination of technological and other
development activities lead to a major increase in the process of urbanization
and this has affected the land use, housing, migration and floating
popu-lation. Let us study these effects one by one.
(1) Land use :
India has the fourth largest urban population in the world. In 1981, its urban
population was 159.73 millions. As the urban population grows, new cities and
towns make their appearance. Such establishments use productive land and rich
forest areas for their settlements. Thus land with all its biological resources
is lost.
The pattem is use of land in India is different from
the western countries where specific areas are used for specific activities. In
India, on the othe hand, the residential, industrial and com-mercial activities
are taking place at the same place or even within the same street. The
substan-tial fraction of urban population lives at the back or on the upper
storey of their shops. The industrial areas are also mixed up with residental
and shopping complexes. This type of mixing
is due to the tendency of the people to live nearer
to their working place and to be near the service centers to avoid the joumey.
Another peculiar feature of Indian cities is, that, a large
munber of service units use the road sides, street
sides or other public places for their business.For example, the rehriwalas use
any part of the open land for putting their rehris.
(2) Housing:
The problem of housing is directly related to the increasing population in
cities and towns, For example, it has been estimated that Delhi needs 80,000
new houses every year.The housing demands and infrastructural shortage was
accumulated over the years and is now beyond any appropriate solution,
On the other hand, the urban have solved their
problem by building clusters of huts wherever they find any open place may be
around the cities or even the surroundings of the villages.
This results into slums. The activities of the slums
are worst for environment degradation.Dharavi in Mumbai is Asia's largest slum.
It has spread over 4.5 square kilometer of prime land of central Mumbai. Its
stable population is estimated to be around three lacs and on an average eight
persons live in each hutment.
Migration : In most of the urban areas, the majority
of the people are not of urban origin. In fact, they have migrated from
non-urban areas or reasons such as employment, business,education, etc. People
working in state government departments migrate from one city to
another because of transfers. Similarly, the
military personals and those who are employers of central government have to
migrate from one end of the country to another. The people working as salesman
keep moving constantly. Due to this, a family has to bear lot of stress.
Not only that it has to move its household but also
it has to adapt to new living conditions,new neighbourers, new house, etc.
(4) Floating population :
It comprises people who commute daily from one place to another to earn their
bread and butter. Ludhiana is Punjab and Chandigarh (Union Tesitory) have a
sub-
stantial number of people that daily travel by buses
or trains to their working place. At the national level, same is the case in
Delhi and Mumbai. The bulk of this floating population com-
It can be concluded that urbanisation has varied
impact on the environment. On one hand, it has deteriorated the environment
both physically and mentally and on the other hand, urbanization is
unavoidable for a developing society.
EXERCISE
(A) Very short answer type questions (1
mark each) :
1. Whatis urbanisation?
2. What ace slums?
3. Define groundwater.
4. What is rotation of crops?
5. Whatis smog?
6. How is the green house effect created?
7, Name the minerals that can be obtianed from sea
floor?
(B) Short answer type questions (2
marks each) :
1. How does migration influence urban environment?
2. Write a short note on floating population.
3. Why are people shifting to urban areas, give
reasons?
4, Name two human activities that lead to soil
erosion?
5. Write a note on vehicular emission.
6. How has human activities resulted in depletion of
forests?
(C) Short answer type questions (4
marks each):
1. What are the effects of non equitable
distribution of natural resources on the develop-ment?
2. How are land and water being pollutd by the urban
people?
3. Write a short note on land use pattern.
4, Discuss main problems of urban areas.
(D) Long answer type questions: (5
marks each):
1. How are civic amentities necessary for
improvement of life? What will be the impact of population explosion on thee
amentities?
2. Discuss the environmental problems of the rural
areas?
