ES FIRST MID ANSWERS FOR ASSIGNMENT1

1a). Definition, Scope and importance of Environmental Studies:
Environment is derived from french word envirroner which means to encircle or to surround. All the living and non-living components surrounding an organism form its environment.
Environmental studies is the process of educating the people for preserving quality environment. The main scope of environmental studies includes:
- To get awareness and sensitivity to the total environment and its related problems.
- To motivate the active participation in environmental protection and improvement.
- To develop skills for identifying and solving environmental problems.
- T o know the necessity of conservation of natural resources.
- To evaluate environmental programs in terms of social, economic, ecological and aesthetic factors.
- Environment protection and management, environmental laws, business administration and environmental engineering are emerging as new carrier opportunities.
- Environmental Science will be a growing field for the future with the growing concerns about our global warming and climate changes. Its scope is so wide that it has got relation with every science and scientific aspects in general and biology in particular and other fields such as ecology, botany, and meteorology besides all other major branches of the science, arts and commerce.

The Importance of environmental studies is extremely high in every major discipline, especially in the following aspects:
- Natural resources (flora, fauna, air, water, land, minerals)
- Biological diversity
- Marine life
- Inter-dependence of man and environment
- Environmental degradation
- Environmental problems and hazards
- Environmental pollution _ air, water, soil, noise
- Waste management
- Disaster management
- Protection of human health conditions and quality of life
- Conservation of energy, soil, wildlife, forests, water
- Renewable resources
- Eco-friendly and indigenous technologies
- Water resources management
- Sustainable development
- Sustainable agriculture
- Environmentally sound management of biotechnology
- Environmental policies and programs
- Environmental information resources
- Acts, laws and regulations
- Role of government and non-governmental agencies.



1 b). What are the various employment potential for environmental subject experts?
- There is a need for trained manpower at every level to deal with environmental issues like safe and clean drinking water, hygienic living conditions, clean and fresh air, fertile land, healthy food and sustainable development.
- Environment protection and management, environmental laws, business administration and environmental engineering are emerging as new carrier opportunities.
- Since the pollution control laws becoming more stringent, industries need environment experts to control pollution and disposal of wastes.
- Environmental experts are now in great demand in industries for adopting green technologies to reduce pollution and to cut down the costs of effluent treatment.
- These days, there is huge market world over for waste disposal and pollution control technologists and environmental experts.
- If we want to live in a clean, healthy, aesthetically beautiful, safe and secure environment for a long time and wish to hand over clean and safe earth to our children, we will have to include environmental experts in all developmental and policy making committees.
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2 a). i. Timber extraction:
Since ancient times, the extraction of timber and the use of wood has been one of man's most fundamental developments. From the implements used in daily life to the buildings that give him shelter and security, man has found wood a uniquely useful utility. Timber production and other wood-based industries still comprise an important part of economy of many countries. Paper production and other industries such as furniture making also important to a nation’s economy.
Commercial logging, a common form of deforestation is cutting trees for sale as timber and pulp. Logging for valuable timber, such as teak and mahogany not only involves a few large trees per hectare but about a dozen more trees since they are strongly interlocked with each other by vines etc., Also road construction for making approach to the trees enable landless people to access the interiors of the forest, which in turn results in further deforestation and poaching. Timber extraction also leads to soil erosion, loss of fertility, landslides, loss of biodiversity, loss of tribal culture and extinction of tribal people.
Classification of timber extraction:
- Clear felling: ..
- Selective logging: ..
- Mechanized logging: …
- Hand logging: ..
- Reduced impact logging: ..
ii. Effects of dams & mining on forests:
Mining, industrial development and Hydro electrical dams also significant causes of deforestation, both in terms of the land they occupy and their influence on degradation of forest and wildlife habitat. The impact of large dams on ecosystems are more negative than positive and in many cases, this has led to serious irrecoverable loss of species and ecosystems. Dams also open up previously inaccessible forest and damage downstream ecosystems. The emission of the greenhouse gases from reservoirs due to rotting vegetation and carbon inflows from the catchment area is a one more recently identified impact. Dams causes water-logging and salinization of the surrounding lands
Mining operations for extracting minerals and fossil fuels such as coal often involves vast forest areas. Mining and its associated activities require removal of vegetation along with underlying soil mantle and overlying rock masses. This results in defacing the topography and destruction of the landscape in the area. The forest area has declined at an average rate of 33% and the increase in non-forest area due to mining activities has resulted in relatively unstable zones leading to landslides. Mining increases access to otherwise remote forest areas and provide an opportunity for further activities, especially in places where population pressures already exist.
2 b). What are the methods of water conservation?
‘CATCH THE RAIN WHERE IT POURS’
Rainwater Harvesting:
Rainwater harvesting is the gathering and collection of water from the rooftop. The traditional method of rain water harvesting is the most effective and simple way to conserve the water. It means utilization of rain water for the domestic as well as agricultural purposes. There are three technical methods of rain water harvesting such as Catchment, Conveyance and storage.
Watershed Management:
Rivers originate in streams that flow down mountains and hill slopes. A group of small streams flow down hillsides to meet larger streams in the valley which forms the tributaries of major rivers. The management of a single unit of land with its water drainage system is called watershed management. It is a technique that has several components. This includes soil and water management and developing vegetative cover. The natural drainage pattern of a watershed unit if managed appropriately can bring about local prosperity by a year round abundance of water that improves the quality of human life in the area.
By constructing a series of long trenches and mounds along contours of the hill to hold the rainwater and allow it to percolate into the ground. This ensures that underground stores of water are fully recharged. This is enhanced by allowing grasses and shrubs to grow and by planting trees (mainly local species) which hold the soil and prevents it from being washed away in the monsoon. Local grass cover can however only increase if free grazing of domestic animals is prevented by stall feeding. The next measure is to make ‘nala’ plugs in the streams so that the water is held in the stream and does not rush down the hillside. In selected sites, several small check dams are built which together hold back larger amounts of water. All these measures constitute sound watershed management. It improves the water table and keeps the streams and nalas flowing throughout the year.

The 3 R’s ( Reduce, Reuse and Recycle )
Reduce:
- Use only as much water as you require.
- Close the tap well after use.
- While brushing your teeth do not leave the tap running, open it only when you require it.
- See that there are no leaking taps. Get a plumber to come in and seal all leaks.
- Use a washing machine that does not consume too much water.
- Do not leave the taps running while washing dishes and clothes.
- Install small showerheads to reduce the flow of water.
- Water in which the vegetables and fruits have been washed can be used to water the flowers and ornamental potted plants.
- Educate the mind of the people in the rural areas to save the water.
- Never throw the water unnecessary on roads which can be used for gardening and cleaning.
- Avoid unnecessary flushing the toilets. Dispose off the tissues, cigarettes and other waste into the bin instead of toilets.
- Water your lawn only when it is needed.
- Use a broom instead of hose to clean the sidewalks or to wash the car.
Recycle:
- Recycle the hot water from industries by using cooling towers etc.,
- Municipalities should equip sewage treatment plants at every level to reduce the water pollution levels and if purified efficiently can be used for the domestic supply once again.
Reuse:
- Never throw the water unnecessary on roads which can be used for gardening and cleaning.
- At the end of the day if you have water left in your water bottle do not throw it away, pour it over some plants.
- Use the remained soap water
- Reuse the water that vegetables are washed in for watering houseplants or for cleaning.
- When washing clothes by hand, the water should not be left running. Fill a laundry tub with water, and reuse wash and rinse water as much as possible. The used soapy water can be used for cleaning your country yard or garage area.

3 a). Explain the need of conservation of mineral resources.
A mineral is a naturally occurring substance of definite chemical composition and identifiable physical properties. An ore is a mineral or combination of minerals from which a useful substance, such as a metal, can be extracted and used to manufacture a useful product. Minerals are formed over a period of millions of years in the earth’s crust. Iron, aluminum, zinc, manganese and copper are important raw materials for industrial use. Important non-metal resources include coal, salt, clay, cement and silica. Stone used for building material, such as granite, marble, limestone, constitute another category of minerals. Minerals with special properties that humans value for their aesthetic and ornamental value are gems such as diamonds, emeralds, rubies. The luster of gold, silver and platinum is used for ornaments. Minerals in the form of oil, gas and coal were formed when ancient plants and animals were converted into underground fossil fuels.

Minerals are a non-renewable resource. It takes thousands of years for the formation and concentration of minerals. The rate of formation is much smaller than the rate at which the humans consume these minerals. Most of the minerals deposits such as fossil fuels may exhaust in near future. Mining causes devegetation and defacing of landscapes, earthquake, subsidence of land, Ground and surface water pollution, lowering water table, air pollution, occupational health hazards so, it is necessary to reduce wastage in the process of mining.
Minerals can be conserved in by the following measures:
• Use of improved technologies to allow use of low grade minerals at low costs.
• Using substitutes for the non-renewable resources.
• Use of scrap metals
• Recycling of metals is good way in which the mineral resources can be conserved efficiently.
• Mining safety.

3 b). Non-Conventional Energy Sources
The sources of energy which are being produced continuously in nature and are in exhaustible are called renewable sources of energy (or) non-conventional energy.
Some of these sources are:
(a) Wind energy
(b) Tidal energy
(c) Solar energy
(d) Geothermal Energy
(e) Ocean thermal energy
(f) Biomass energy

(a) Wind energy:
Winds are caused because of two factors.
1. The absorption of solar energy on the earth’s surface and in the atmosphere.
2. The rotation of the earth about its axis and its motion around the Sun.
A wind mill converts the kinetic energy of moving air into Mechanical energy that can be either used directly to run the Machine or to run the generator to produce electricity.

(b) Tidal energy
Tides are generated primarily by the gravitational attraction between the earth and the Moon. They arise twice a day in Mid-Ocean. The tidal range is only a Meter.
Basically in a tidal power station water at high tide is first trapped in a artificial basin and then allowed to escape at low tide. The escaping water is used to drive water turbines, which in turn drive electrical generators.

(c) Solar energy
Energy from the sun is called solar energy. The Sun’s energy comes from nuclear fusion reaction that take place deep in the Sun. Hydrogen nucleus fuse into helium nucleus. The energy from these reactions flow out from the sun and escape into space.
The solar energy that falls on India in one minute is enough to supply the energy needs of our country for one day. Man has made very little use of this enormous amount of solar energy that reaches the earth.

Solar Energy applications:
1. Heating and cooling of residential building.
2. Solar water heating.
3. Solar drying of agricultural and animal products.
4. Salt production by evaporation of seawater.
5. Solar cookers.
6. Solar engines for water pumping.
7. Solar Refrigeration.
8. Solar electric power generation.
9. Solar photo voltaic cells, which can be used for electricity.
10. Solar furnaces.

(d) Geothermal energy:
Temperature of the earth increases at a rate of 20° to 75°C per km, when we move down the earth surface. High temperature and high pressure steam fields exist below the earth’s surface in many places. The energy harnessed from the high temperature present inside the earth is called geothermal energy.
Natural Geysers and Artificial Geysers.

(e) Ocean thermal energy:
There is often large temperature difference between the surface level and deeper level of the tropical oceans. This temperature difference can be utilized to generate electricity or heating.
The energy due to the difference in temperature (around 20°C ) of water is called ocean thermal energy.

(f) Biomass energy:
Biomas is the organic matter, produced by plants or animals, used as source of energy. Most of the biomass is burned directly for heating, cooling and industrial purposes.

Biogas: is a mixture of methane, CO2 and H2S. Biogas contains 65% of methane gas as a major constituent. Biogas is obtained by the anaerobic fermentation of animal dung or plant wastes in the presence of water

Biofuels: Ethanol, methanol and Gasohol.

Hydrogen fuel: Hydrogen can be produced by thermal dissociation or photosynthesis or electrolysis of water. It posses high calorific value. It is non-polluting, because the combustion product is water.