22. Environmental Management

I. Fill in the blanks.

1. Deforestation leads to Reduction in rainfall.

2. Removal of soil particles from the land is called Soil erosion

3. Chipko movement is initiated against the cutting down of trees

4. Nilgiris is a biosphere reserve in Tamilnadu.

5. Tidal energy is Non-conventional or renewable type of energy.

6. Coal, petroleum and natural gas are called Fossil fuels.

7. Coal is the most commonly used fuel for the production of electricity.

II. State whether True or False. If false, write the correct statement:

1. Biogas is a fossil fuel.
Answer:           False
Correct statement: Biogas is the mixture of methane, hydrogen sulphide, carbon-di-oxide and hydrogen.

2. Planting trees increase the groundwater level.
Answer:           True

3. Habitat destruction caused loss of wildlife.
Answer:           True

4. Nuclear energy is renewable energy.
Answer:           False
Correct statement: Nuclear energy is a non-renewable energy source. The material used in nuclear plants is not renewable.

5. Overgrazing prevents soil erosion.
Answer:           False
Correct statement: During overgrazing, most of the plants are eaten up. If the plants or vegetation is retained, the soil is not exposed. Soil erosion occurs due to overgrazing.

6. Poaching of wild animals is a legal act.
Answer:           False
Correct statement: Poaching should be prohibited.

7. The national park is a protected park.
Answer:           True

8. Wildlife protection act was established in 1972.
Answer:           True

III. Match the following:

Column A

Column B

1. Soil erosion

(c) removal of vegetation

2. Bio-gas

(d) renewable energy

3. Natural gas

(f) non-renewable energy

4. Greenhouse gas

(e) CO2

5. CFL bulbs

(a) energy saving

6. Wind

(b) acid rain

7. Solid waste

(g) lead and heavy metals

IV. Choose the correct answer:

1. Which of the following is/are a fossil fuel?
i. Tar   ii. Coal            iii. Petroleum

(a) i only
(b) i and ii
(c) ii and iii
(d) i, ii and iii
Answer:
(c) ii and iii

2. What are the steps will you adopt for better waste management?

(a) reduce the amount of waste formed
(b) reuse the waste
(c) recycle the waste
(d) all of the above

3. The gas released from vehicles exhaust is _________
i. Carbon monoxide
ii. Sulphur dioxide
iii. Oxides of nitrogen

(a) i and ii
(b) i and iii
(c) ii and iii
(d) i, ii and iii

4. Soil erosion can be prevented by:

(a) deforestation
(b) afforestation
(c) over growing
(d) removal of vegetation

5. A renewable source of energy is ______

(a) petroleum
(b) coal
(c) nuclear fuel
(d) trees

6. Soil erosion is more where there is:

(a) no rain fall
(b) low rainfall
(c) rain fall is high
(d) none of these

7. An inexhaustible resources is _______

(a) wind power
(b) soil fertility
(c) wildlife
(d) all of the above

8. Common energy source in village is:

(a) electricity
(b) coal
(c) biogas
(d) wood and animal dung

9. The greenhouse effect refers to _____

(a) cooling of Earth
(b) trapping of UV rays
(c) cultivation of plants
(d) warming of Earth

10. A cheap, conventional, commercial and inexhaustible source of energy is:

(a) hydropower
(b) solar energy
(c) wind energy
(d) thermal energy

11. Global warming will cause _______

(a) raise in the level of oceans
(b) melting of glaciers
(c) sinking of islands
(d) all of these

12. Which of the following statement is wrong with respect to wind energy?

(a) wind energy is a renewable energy
(b) the blades of wind mill are operated with the help of electric motor
(c) production of wind energy is pollution free
(d) usage of wind energy can reduce the consumption of fossil fuels

V. Answer in a Sentence.

1. What will happen if trees are cut down?

Soil erosion occurs and ecological imbalance takes place if trees are cut down.

2. What would happen if the habitat of wild animals is disturbed?

If the habitat of wild animal is disturbed it leads to extinction of animals or on the verge of extinction.

3. What are the agents of soil erosion?

The high velocity of wind, air currents, flowing water, landslide, human activities such as deforestation, farming and mining, and overgrazing by cattle are the agents of soil erosion.

4. Why fossil fuels are to be conserved?

The formation of fossil fuels is a very slow process and takes very long period of time for renewals so fossil fuels are to conserved.

5. Solar energy is renewable energy. How?

Solar energy is renewable, free source of energy, that is sustainable and totally inexhaustible.

6. How are e- wastes generated?

e-wastes are spoiled, out dated, non-repairable, electrical and electronic devices like computer components electronic and electrical appliances.

VI. Short Answer Questions

1. What is the importance of rainwater harvesting?

The importance of rainwater harvesting is as follows:

  • overcome the rapid depletion of groundwater levels.
  • To meet the increased demand for water.
  • Reduces flood and soil erosion.
  • Water stored in-ground is not contaminated by human and animal wastes and hence can be used for drinking purpose.

2. What are the advantages of using biogas?

1.      It bums without smoke and therefore causes less pollution.

2.      An excellent way to get rid of organic wastes like bio-waste and sewage material.

3.      Left over slurry is a good manure rich in nitrogen and phosphorus.

4.      It is safe and convenient to use.

5.      It can reduce the amount of greenhouse gases emitted.

3. What is the environmental effect caused by sewage?

·         Sewage is the leading polluter of water resources in India.

·         Different species of fishes are killed.

·         Contaminated water can cause diseases such as e-coli, diarrhoea and hepatitis A.

4. What are the consequences of deforestation?

Deforestation gives rise to ecological problems like floods, drought, soil erosion, loss of wild life, extinction of species, imbalance of biogeochemical cycles, alteration of climatic conditions and desertification.

VII. Long Answer Questions

1. How does rainwater harvesting structures recharge groundwater?

Rainwater harvesting is a technique of collecting and storing rainwater for future use. The main purpose of rainwater harvesting is to make the rainwater percolate under the ground, so as to recharge ‘groundwater level’.

Methods of rainwater harvesting
(i) Rooftop rainwater harvesting: The rainwater that falls on the roof of the houses, apartments and commercial buildings, etc, is collected and stored in the surface tank and is used for domestic purpose.

(ii) Recharge pit: The collected rainwater is directed into the percolation pits through pipes for Alteration. After Alteration, the rainwater enters the recharge pits or ground wells.

  • Digging of tanks or lakes (Eris): Eris is constructed in such a way that, if the water in one eri overflows, it automatically gets diverted to the eri of the next village, as these eris are interconnected.
  • Ooranis: These are small ponds to collect rainwater. They are used for various domestic purposes.

2. How will you prevent soil erosion?

1.      Retain vegetation cover, so that soil is not exposed.

2.      Cattle grazing should be controlled.

3.      Crop rotation and soil management improve soil organic matter.

4.      Runoff water should be stored in the catchment.

5.      Reforestation, terracing and contour ploughing.

6.      Wind speed can be controlled by planting trees in form of a shelter belt.

3. What are the sources of solid wastes? How are solid wastes managed?

Solid wastes mainly include municipal wastes, hospital wastes, industrial wastes and e-wastes, etc. The solid wastes are dumped in the soil, which results in landscape pollution. Solid-waste management involves the collection, treatment and proper disposing of solid material that is discarded from the household and industrial activities.

Methods of solid wastes disposal:

  • Segregation: It is the separation of different type of waste materials like biodegradable and non-biodegradable wastes.
  • Sanitary landfill: Solid wastes are dumped into low lying areas. The layers are compacted by trucks to allow settlement. The waste materials get stabilised in about 2-12 months. The organic matter undergoes decomposition.
  • Incineration: It is the burning of non-biodegradable solid wastes (medical wastes) in the properly constructed furnace at high temperature.
  • Composting: Biodegradable matter of solid wastes is digested by microbial action or earthworms and converted into humus.

4. Enumerate the importance of forest.

Forests are an important component of our environment and are dominated by microorganisms, flowering plants, shrubs, climbers, dense trees and provide a vast habitat for wild animals. Forests also contribute to the economic development of our country. Forests are vital for human life, it is a source for a wide range of renewable natural resource. They provide wood, food, fodder, fibre and medicine.

Forests are major factor of environmental concern. They act as a carbon sink, regulate climatic conditions, increase rainfall, reduce global warming, prevent natural hazards like flood and landslides, protect wildlife and also act as catchments for water conservation. They also play a vital role in maintaining ecological balance.

5. What are the consequences of soil erosion?

The consequences of soil erosion are as follows:

  • It has led to increased pollution and sedimentation in streams and rivers.
  • Clogging the waterways and causing a decrease in fish species.
  • Degraded lands often have less ability to hold on to water.
  • Topsoil is removed.
  • Topsoil quality is reduced.
  • No medium crops to grow in soil with poor quality.
  • Use of artificial fertilizers.
  • Disrupts ecosystem.

6. Why is the management of forest and wildlife resource considered as a challenging task?

People would consider forest is a source of raw materials for the factories and industries, and utilise it for development of human without considering about other organism. There are many stake holders of forest. They are those people who are directly or indirectly involved in forest. Management of forest and called life has to take into account the interest of all stake holders which become a challenging task.

VIII. Assertion and Reasoning Questions

In each of the following question, a statement of assertion (A) is given and a corresponding statement of Reason (R). Of the four statements given below mark the correct answer.
(a) Both assertion and reason are true and the reason is the correct explanation of assertion.
(b) Both assertion and reason are true but the reason is not the correct explanation of assertion.
(c) Assertion is true but the reason is false.
(d) Both assertion and reason are false.

1. Assertion: Rainwater harvesting is to collect and store rainwater.
Reason: Rainwater can be directed to recharge the underground water source.
Answer:
(a) Both assertion and reason are true and the reason is the correct explanation of assertion.

2. Assertion: Energy-efficient bulbs like CFL must be used to save electric energy.
Reason: CFL bulbs are costlier than ordinary bulbs, hence using ordinary bulbs can save our money.
Answer:
(c) Assertion is true but the reason is false.

IX. Higher Order Thinking Skills (HOTS) Questions

1. Although coal and petroleum are produced by the degradation of biomass, yet we need to conserve them. Why?

·         The coal and petroleum reserves can get exhausted, if we use them at a rapid rate.

·         The formation of fossil fuel is a very slow process and takes a very long time for renewal.

·         It is necessary to conserve the resource, for the future generation, by reducing their consumption.

2. What are the objectives for replacing non-conventional energy resources from conventional energy resources?

Non conventional energy resources are non-polluting renewable sources which are environmentally clean. It is available in unlimited amount in nature and they can be renewed over a short period of time inexpensive and can be harvested continuously.

3. Why is the Government imposing a ban on the use of polythene bags and plastics? Suggest alternatives. How is this ban likely to improve the environment?

Government is imposing a ban on the use of plastic bags and plastics because,

  • Plastics pollute on land, rivers, ponds and all water bodies and soil, etc.
  • Burning of plastic in open air leads to environmental pollution, due to the release of poisonous gas.
  • The accumulation of plastic bags and plastics prevent the seeping of water into the Earth, which brings down the levels of groundwater.
  • Plastic bags can travel long distances by wind and water. They litter our landscapes and water bodies.

Alternatives:

  • Bring your own containers and bags to buy things from the shop.
  • Use paper wraps or compostable bags with cloth or brown paper.

Improvement of the environment on plastic ban:

  • Improve the health of individuals.
  • Driving to innovate alternatives.
  • Plastic pollution reduced.
  • The nation is safe.

X. Value-Based Questions

1. Why is it not possible to use solar cells to meet our energy needs? State three reason to support to your answer.

In solar cells, the solar panel convert solar energy into electricity, which stored in storage battery. The storage battery gives direct current, which is to be converted into alternating current by an suitable appliances before it can be used to run various, devices. So, it increases the cost of using panels as the source of energy.

In the solar cells the energy is obtained only during the day, when the sun shines. So the solar cells is not used to meet our energy needs.

2. How would you dispose of the following wastes?

  1. Domestic wastes like vegetable peels
  2. Industrial wastes like metallic cans

Can the disposal protect the environment? How?

Domestic wastes have to be thrown out with the trash.

  1. Do vermiform composting system for vegetable wastes which can be used as a manure. Industrial wastes like metallic cans can be recycled.

3. List any three activities based on 3R approach to conserve natural resources.

Recycling : Using recycled material of glass plastic, paper, metal etc.
Reuse : Repeating use of items.
Reduce : Avoid the use of materials which increases the solid waste.
Use of public transport instead of personal transport to reduce to consumption of fuel. Use of materials such as paper should be preferred.