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Dr. Pavithra B S
Assistant Professor (Forest Protection)
Environmental Studies and Disaster
Management

Introduction
 Environment is defined as it is the sum total of all conditions and
influences that affect the development and life of all organisms on
earth.
 The living organisms vary from the lowest micro-organisms such as
bacteria, virus, fungus, etc. to the highest, including man. Each
organism has its own environment (physical and biological).
 The word “environment” originates from “environ” which means things
that surround. As per definition of the Environment Protection Act,
environment includes all the physical and biological surroundings and
their interactions.
 The study of environment or rather environmental studies is a multi-
disciplinary subject which needs knowledge interest from physical
sciences, biological sciences, social sciences etc.
 Environmental studies has a broad base, which requires integrated
approach for dealing with the various aspects.

SCOPE
Environmental studies as a subject has a wide scope. It encompasses a
large number of areas and aspects
 Natural resources — their conservation and management
 Ecology and biodiversity
 Environmental pollution and control
 Social issues in relation to development and environment
 Human population and environment
These are the basic aspects of environmental studies which have
a direct relevance to every section of the society.

Several career options have emerged in this field that are broadly categorized as:
(i) Research & Development (R & D) in environment:
 Environmental management and environmental engineering are emerging as new
career opportunities for environmental protection and management.
 Investing in pollution control technologies will reduce pollution as well as cut on
costs for effluent treatment.
 Cleaning up of the wastes produced is another potential market.
(ii) Green advocacy:
 With increasing emphasis on implementing various Acts and laws related to
environment, need for environmental lawyers has emerged, who should be able
to plead the cases related to water and air pollution forest, wildlife etc.

(iii) Green marketing:
 While ensuring the quality of products with ISO mark, now there is
an increasing emphasis on marketing goods that are environment
friendly. Such products have ecomark or ISO 14000 certification.
Environmental auditors and environmental managers would be in
great demand in the coming years.
(iv) Green media:
 Environmental awareness can be spread amongst masses through
mass media like television, radio, newspaper, magazines, hoardings,
advertisements etc. for which environmentally educated persons are
required.
(v) Environment consultancy:
 Many non- government organizations (NGOs), industries and
government bodies are engaging environmental consultants for
systematically studying and tackling environment related problems.

Importance of environment
 Issues like global warming, depletion of ozone layer dwindling forests
and energy resources, loss of global biodiversity etc. which are going to
affect the mankind as a whole are global in nature.
 However, there are some environmental problems which are of localized
importance. For dealing with local environmental issues, e.g impact of
mining or hydro-electric project in an area, problems of disposal and
management of solid waste, river or lake pollution, soil erosion, water
logging and salinization of soil, fluorosis problem in local population,
arsenic pollution of groundwater etc.
 Environmental studies deals with individual matters, like dealing with
safe and clean drinking water, hygienic living conditions, clean and fresh
air, fertile land, healthy food and sustainable development.

Introduction of Environmenal studies.pptx

Human activities and their impact on environment
Agriculture
(i) Traditional Agriculture and its Impact:
 It involves small plots, simple tools, natural water, organic fertilizer and several
crops. The yield is, however, low but it is still used by about 50% of the world
population. The impacts of this type of agriculture are as follows:
(a) Depletion of Nutrients:
 During slash and burn of trees in forests, the organic matter in soil is destroyed
and within a short period most of the nutrients are taken up by the crops. Thus
the soil becomes deficient in nutrients and compels the cultivators to shift to
another area.
(b) Deforestation: Forest land is cleared by slash and burn of trees in forest for
cultivation purposes.
 Frequent shifting of cultivation plots leads to deforestation i.e., loss of forest
cover.
(c) Soil Erosion:
 As a result of deforestation, soil gets exposed to the weathering forces i.e., rain,
wind and storms and is subjected to erosion. The net result is loss of top fertile
soil.

(ii) Modern Agriculture and its Impact:
(a) Impacts from HYV (High-Yielding Varieties): Application of seeds of
HYV gave rise to monoculture i.e., the same species (genotype)
grown over vast areas, such monoculture is vulnerable to attack by
some pathogen, which spreads like wild fire, devastating crops over
large areas.
(b) Fertilizer Problems: Essential micronutrients— nitrogen, phosphorus
and potassium (NPK) are supplied by chemical fertilizers.
Indiscriminate use of chemical fertilizers causes micronutrient
imbalance in the soil which ultimately loses productivity.
(c) Nitrate Pollution: From agricultural fields nitrogenous fertilizers
leach into the soil and finally contaminate groundwater. When the
nitrate level of groundwater exceeds 25 mg/l, they can cause a serious
health hazard known as “Blue Baby Syndrome”, which affects mostly
infants even leading to their death.
(d) Eutrophication: Agricultural run-off water contains fertilizer
components, particularly nitrogen and phosphorus, which reaches
nearby water bodies and causes their over nourishment. Excessive use
of these fertilizers leads to over nourishment of the lakes/waterbodies
and gives rise to the phenomenon of eutrophication.

Pesticide Side Effects:
 Several thousand pesticides are used in agriculture for destroying pests
and boosting crop production.
 From 1940 synthetic organic pesticides have been used. Among these,
DDT (dichlorodiphenyl trichloroethane), discovered by Paul Mueller
(1939). During 1940-1950, it saved 5 million lives from malaria, typhus
etc. and also protected crops from huge losses. But DDT and other
pesticides show a number of harmful side-effects on environment.
(a) Inducing Pest Resistance and Yielding New Pests: In course of time
new generations of pests develop resistance to pesticides so that they
survive even after pesticide spray.
(b) Biological Magnification/Amplification: Many pesticides including
DDT are non-biodegradable so that they persist in the food chain. At
each step of the food chain the pesticide level gets more and more
concentrated. This is the process of biological magnification or
amplification. Thus, DDT builds up from 0.04 ppm in plankton to 75
ppm in fish-eating birds. Man occupies a high trophic level in the food
chain and hence gets a high dose of pesticide, which is quite harmful.

(iv) Waterlogging:
 Excessive irrigation of croplands for good growth of crop leads to
waterlogging. In the absence of adequate drainage, excess water is
accumulated which seeps into the underlying water table. Pore spaces
in the soil get fully drenched with water and soil-air becomes deficient.
The water table rises and the roots of plants have insufficient air for
respiration. There is decline in crop yield with decrease in soil
strength.
(v) Salinity Problem:
 In addition to waterlogging, salinity also rises from excessive
irrigation water. The latter contains dissolved salts which under dry
conditions evaporates leaving behind salts in the upper soil profile.
Saline soils are characterized by accumulation of soluble salts such as
sodium chloride, sodium sulphate, calcium chloride, magnesium
chloride etc. in the soil profile.
 Salinity causes stunted plant growth and reduces crop yield. Thousands
of hectares of land in Haryana and Punjab have been affected by soil
salinity.

Industry
 Industries produce environmental hazards everywhere. They consume
37 per cent of world’s energy and emit 50 per cent of world’s CO₂, 90
per cent of SO₂ and almost all the chemicals now threatening O₂ layer
with depletion.
 Every year, they produce 2100 million tonnes of solid waste and 350
million tonnes of hazardous waste. In developing countries, small as
well as big industries discharge untreated waste.
 There is world-wide concern about the disposal of radioactive wastes
from nuclear reactors.

Mining:
 Mining involves extraction of minerals/fossil fuels from deep deposits
in soil employing the techniques of sub-surface mining or surface
mining.
(a) De-vegetation and Defacing of Landscape: Large-scale de-vegetation
or deforestation leads to ecological imbalances.
(b) Subsidence of Land: Underground mining (e.g., coal) causes
subsidence of the soil above resulting in tilting of buildings, cracks in
soil/road, bending of rail tracks etc.
(c) Groundwater Contamination: Sulphur impurity in many areas gets
converted into sulfuric acid, which makes the water acidic and
contaminates the nearby streams and lakes and damages aquatic life.
(d) Air Pollution: Emit huge volumes of air pollutants—sulphur oxides,
arsenic, lead, cadmium particles etc. These have public health hazards
for local residents.
(e) Occupational Health Hazards: Most of the miners suffer from
various respiratory and skin diseases due to constant exposure to the
suspended particulate matter and toxic substances. Such diseases
include asthma, bronchitis, black-lung disease etc.

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Introduction of Environmenal studies.pptx

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