WBBSE Solutions For Class 8 Geography Chapter 7 Human Activities and Environmental Degradation Topic A Consequences And Control Of Environmental Degradation

Chapter 7 Human Activities and Environmental Degradation Synopsis

The physical and biotic processes of nature have a self-regulatory style of working. Any change or damage caused by them to the environment is naturally restored, compensated or adjusted. This is called a homeostatic mechanism.

The Industrial Revolution in Europe in the eighteenth century was a giant step in the advancement of human civilization.

Environmental degradation means the overall lowering of environmental qualities because of adverse changes brought about by natural processes and human activities.

The main causes of environmental degradation are soil erosion, deforestation, floods, desertification, and loss of biodiversity.

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The degradation of any component of the environment caused by natural processes or human activities is called Environmental pollution.

Bhopal Gas Tragedy occurred in December 1984 due to the leakage of Methyl Isocyanate gas from a plant of the Union Carbide Factory.

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The Chornobyl disaster occurred in April 1986 in a nuclear reactor plant in Chornobyl.

The Fukushima Daiichi accident occurred in March 2011 in a nuclear power plant in Fukushima Daiichi.

Sustainable development refers to development aimed at the optimum use of natural resources in the present scenario so that development can take place without the environment being hampered and also preserving the reserves of nature and the potential of human society to develop, for future use.

Lack of education and poverty are the two main indirect causes of environmental degradation.

Earth Summit or Rio Summit was another name for the United Nations Conference on Environment and Development. It was held in Rio de Janeiro, Brazil, from 3 June to 14 June 1992. 178 nations and more than 30 thousand people participated in this conference.

Ganga Action Plan (GAP) has been taken up to make the Ganga pollution free and maintain the ecological balance. This project was officially initiated in Varanasi on January 14, 1986.

G20 or Group of 20 is an international association formed by 20 countries. This group came into being in 1999 and now has a total membership of 20 nations (2017). It was created primarily to develop trade relations among its member nations.

The full form of WHO is World Health Organisation. Its headquarters is in Geneva in Switzerland. As an agency of the United Nations, WHO is responsible for issues on public health around the world. It plays an important role in the eradication of diseases.

The Chipko movement was started in 1973 in the Garhwal region of Uttarakhand in order to protect trees. The name of the movement came from the Hindi word ‘Chipko meaning ‘to embrace’, as the villagers hugged the trees and prevented the contractors from felling them.

The Green Revolution in India has contributed much in improving crop production and the overall condition of agriculture of the country. But it also exerted some negative impacts such as degradation of soil fertility, change in biodiversity and genetic modification of the seeds, etc.

We, the students, can contribute much in keeping our environment clean by reducing waste, planting saplings, organizing seminars and rallies, etc.

Chapter 7 Topic A Consequences And Control Of Environmental Degradation Analytical Type Questions

Question 1. How has the evolution of human civilisation affected the environment?
Answer:

Evolution Of Human Civilisation Affected The Environment:-

On the basis of primary means of subsistence, human beings can be said to have evolved through different phases. These are divided as- hunter-gatherer, pastoral, agrarian, and industrial phases.

Hunter-gatherer phase:

In this phase, human beings used to sustain themselves by gathering fruits and hunting animals in the forests. They did not cause any change or damage to the surrounding environment.

Pastoral phase:

With the discovery of fire and awareness of its use, the evolution of civilization took an important turn, which started with the domestication and rearing of animals. Primarily the pastoralists were nomadic.

They reared livestock for milk and meat, but slowly they started exploiting the environment.

Agrarian phase:

Taking up the practice of farming for obtaining food was a notable stage in the evolution of mankind. This resulted in the clearing of forests for agricultural lands and settlements.

The increase in population created an increasing demand for farmlands and slowly human beings began to modify the environment.

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Industrial phase:

The Industrial Revolution from the 1760s marked the beginning of a rapid change in the environment as well as an increase in population.

Demand for land for agriculture, industry, and townships increased and human beings started the indiscriminate exploitation of natural resources.

Human activities, in the name of development, are damaging the environment. which cannot be repaired again. The effect of this can be felt by everyone at present.

Question 2. Classify different kinds of human activities according to their nature and enlist them below. How do you think, these activities influence the human environment?
Answer:

Different kinds of human activities according to their nature and their influence on the environment are enlisted below-

 

Question 3. Discuss the reasons for environmental degradation.
Answer:

Reasons For Environmental Degradation:-

Environmental degradation occurs due to the two following reasons

1. Natural events and
2. Human activities.

1. Natural events:

Different natural events are often responsible for the degradation of the environment.

These include

1. Volcanic activities,
2. Floods,
3. Droughts,
4. Earthquakes,
5. Landslides,
6. Tsunamis,
7. Forest fires,
8. Acid rain,
9. Formation of methane gas,
10. Excessive snowfall snowstorms,
11. Flash floods,
12. Cyclones, etc.

These pollute the environment and lead to its degradation. Normal life cycles of human beings, animals, plants and microbes are disrupted by this.

Human activities:

Some of the primary human activities that cause environmental degradation are-

1. Excessive use of fossil fuels,
2. Population explosion,
3. Unplanned urbanization,
4. Unplanned farming with the help of machinery,
5. Testing of weapons and war equipment,
6. Excessive use of chemical fertilizers and pesticides,
7. Dumping of industrial wastes into lakes, rivers, and seas,
8. Misuse of natural resources,
9. Deforestation,
10. Extraction of excessive mineral resources,
11. Construction of dams on rivers,
12. Indiscriminate use of plastic and other non-biodegradable materials,
13. Establishments of nuclear power plants, etc. Landslide floods, earthquakes, droughts, etc., Are nowadays considered to be greatly related to human activities.

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Question 4. What are the environmental impacts of technology-dependent activities?
Answer:

Environmental Impacts Of Technology-Dependent Activities:-

Technology has made our lives easier, but it also has several adverse effects on the environment. Some of these effects are as follows

1. The burning of coal and mineral oil for the production of thermal power releases SO2, CO2, and other harmful gases into the atmosphere in large amounts. This is one of the main causes of air pollution.
2. The construction of roads also has the same adverse effect on the atmosphere.
3. The construction of dams and hydel power stations are responsible for the destruction of the ecological balance at the construction site.
4. Smoke and untreated water discharged from factories are responsible for polluting air and water.
5. Pollution occurs from almost all kinds of activities related to infrastructural development.

Question 5. Discuss the effects of environmental degradation.
Answer:

Effects Of Environmental Degradation:-

The different effects of environmental degradation are as follows-

1. Pollution:

One of the main effects of environmental degradation is pollution.

This mainly includes

1. Toxic gases released by vehicles running on fossil fuels (petrol, diesel), nuclear power plants, etc., into the atmosphere and render it toxic. for life on earth. This causes air pollution.
2. Dumping of industrial wastes in waterbodies, oil spills in oceans, etc., thus renders the water unsuitable. This causes water pollution.
3. Use of chemical fertilizers, pesticides, excessive irrigation, etc., which wash away the top layer of the soil and thus render it unfit for plant and crop growth, causing soil pollution.

2. Floods and droughts:

Floods and droughts are the results of climatic degradation. Excessive deforestation is one of the main reasons for drought. On the other hand, deforestation also causes flash floods in hilly areas as there is no vegetation cover to absorb the surface runoff during heavy rainfall.

Besides, soil erosion causes the deposition of too much silt in the river beds, causing them to overflow their banks and flood the surrounding areas.

3. Global warming and climatic change:

Practices such as excessive use of fossil fuels and deforestation are increasing the average temperature of the earth. This in turn, is causing the polar ice caps to melt, causing a significant rise in the sea level.

4. Depletion of natural resources:

As the environment gets degraded over time, various mineral resources, forests, drinking water, fertile soil, etc., are slowly depleting from the surface of the earth.

5. Loss of biodiversity:

Several plant and animal species that have evolved on the surface of the earth over thousands of years have been wiped out in the last few centuries. This steady loss in biodiversity is aggravating the rate of degradation of the environment.

6. Earthquakes:

Terrace farming, deforestation and construction of roads in hilly areas, extraction of minerals, unregulated use of groundwater, etc., are all factors that induce earthquakes. Earthquakes occurring in an area degrade the physical and human environment of the area.

7. Diseases:

As the global environment is degrading, human health is getting affected as well. As a result, the rate of occurrence of diseases such as cancer, tuberculosis, malaria, encephalitis, and various lung and heart diseases is rapidly increasing.

8. Chemical Inadequate disaster:

Infrastructure, lack of skilled laborers, upgraded technology not being used, and carelessness on the part of the workers can cause fatal chemical disasters at factories.

9. Inflation and disequilibrium between demand and supply:

Inflation in society is an economic problem. Poor economic decisions, business houses going bankrupt, imports exceeding the exports of a country all lead to inflation. These also disrupt the equilibrium between demand and supply.

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Question 6. Discuss the ways of conserving the environment. Or, How can degradation be controlled?
Answer:

Ways Of Conserving The Environment:-

Environmentalists have suggested several steps to control environmental degradation.

Few of these are

1. Increase in awareness and fighting poverty:

Awareness about the environment needs to be spread so that people understand its importance and hence try to reduce its degradation.

It has been found that environmental degradation is closely related to poverty. Thus, people of economically backward countries need to be made aware through education.

2. Use of eco-friendly forms of energy:

The use of coal, mineral oil, and natural gas should be reduced and instead, alternative and pollution-free eco-friendly forms of energy should be used. Per-capita consumption of energy should be decreased.

Example The increased use of wind energy, solar energy, and other forms of non-conventional sources of energy can prevent further environmental degradation.

3. Recycling of resources:

With the help of technology, resources should be recycled. Recycling and judicious use of resources will prevent the misuse of natural resources. Consumers should be encouraged to buy reusable commodities.

4. Population control:

A balance between the population of a nation and the resources available to it is necessary, or else it is bound to cause degradation of the environment. Thus, regulation of the population in a country is essential.

5. Conservation of biodiversity:

A loss in biodiversity can have adverse effects on the local ecosystem and eventually on the environment. Thus, it is necessary to preserve the natural environment. Man must allow all animals and plants to grow in their natural habitat.

Cleanliness of air, water, soil, and woodlands should be maintained.

6. Planned development:

Urbanization, construction of roads, railways, factories, watershed management, dams on rivers, power plants, etc., should be done in a planned manner, keeping in mind the short and long-term effects they shall have on the environment.

People should be made aware of environmental issues.

7. Implementation of laws:

Special laws regarding the protection of the environment and their strict implementation can reduce and eventually stop environmental degradation at the hands of human beings.

8. Assessing environmental impact of projects:

The environmental impacts of a project or proposal should be assessed properly before their implementation. Steps should be taken so that a development plan does not affect the environment too adversely.

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Question 7. What is meant by eco-friendly forms of energy? Why are these unconventional forms of energy regarded as eco-friendly forms?
Answer:

Eco-friendly forms of energy:

Eco-friendly forms of energy are those which do not harm the environment when they are generated or used. The discovery of solar-powered pumps, engines, cookers, refrigerators, etc., was aimed at the reduction of the use of fossil fuels.

Even though hydel power plants reuse water for generating electricity, hydel power is not considered eco-friendly. This is due to the fact that building a hydel power plant causes great damage to the ecosystem.

Unconventional forms of energy as eco-friendly forms of energy:

Unconventional forms of energy include solar energy, wind energy, tidal energy, geothermal energy, biogas, etc. The above-mentioned forms of energy are eco-friendly because of the following reasons

1. The generation of energy from these forms do not use any non-renewable natural resources. Thus, the environment is not damaged.
2. No fossil fuel is used in the production of these power sources. Therefore the fossil fuel reserves are not used up.
3. The generation of unconventional forms of energy do not cause any kind of pollution.
4. Even though the initial establishment cost to generate this energy is high, later the energy can be obtained practically free of
   cost.
5. There is no chance of global warming in the process of generation of electricity from non-conventional sources.

Therefore, unconventional forms of energy are eco-friendly in nature.

Question 8. How can sustainable development be achieved by any nation?
Answer:

Sustainable Development Be Achieved By Any Nation As Follows:-

The agenda of sustainable development was taken up in the 1992 Earth Summit at Rio de Janeiro, Brazil. Steps taken to achieve sustainable development by any nation are as follows-

1. Environment-friendly technology should be used.
2. Local ecosystems should be looked after and preserved.
3. Steps should be taken to control social problems such as poverty, hunger, and illiteracy.
4. Developmental programs should be implemented according to the environment of a particular place.
5. Efforts should be made in establishing a balance in society between the natural environment and anthropological activities.
6. Levels of pollution should be controlled. Steps should be taken to control the misuse of natural resources.
7. A vigilant eye should be kept on the maintenance of the balance between population and natural resources in a country.
8. Recycling of materials should be done.

Question 9. What are the effects of war on the environment? 
Answer:

Effects Of War On The Environment:-

A war is not only a conflict between two or more nations involving humans, it also causes damage to air, soil, and water resources. The flora and fauna of the region also incur damage due to war.

The effects of war on the environment are-

1. Loss of life:

Loss of life is the inevitable and immediate consequence of war. It is the greatest damage caused to the environment of a place or region.

2. Air pollution:

The explosion of bombs and firing of missiles during a war cause air pollution. The explosion from nuclear bombs degrade the environment.

Hiroshima and Nagasaki are prominent examples of how war affects the environment. Chemical warfare also causes air pollution, killing human beings and other animals.

3. Soil pollution:

The explosions not only damage the air but also damage the soil. The area of land where the explosion occurs is greatly damaged and becomes unfit for use.

4. Water pollution:

Wars are also responsible for causing water pollution. The Gulf War Oil Spill was one of the largest oil spills in the history of mankind which eventually led to the Gulf War.

Oil Spill damages the aquatic ecosystem and leads to the death of numerous aquatic flora and fauna.

5. Morale damage:

War damages human morale also. It creates a lasting fear in people’s minds.

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Question 10. How do multipurpose river valley projects affect the environment?
Answer:

Multipurpose River Valley Projects Affect The Environment:-

Multipurpose river valley projects affect the environment in several ways. These are

1. Earthquakes:

The huge amount of water stored by dams exerts pressure on the underlying rock strata and often causes earthquakes.

For example, the earthquake at Koyna, Maharashtra in 1967.

2. Destruction of forests:

To implement a multipurpose project many canals need to be dug up. This damages forest cover in the surrounding areas.

3. Ecosystem disrupted:

Multipurpose river valley projects create an imbalance in the ecosystem of that area, and that consequently affects the catchment area and the whole river basin.

4. Floods:

An excessive amounts of silt, carried by rivers, gets deposited in the dams. Thus the depth of the dams reduce and the surrounding areas are very often inundated.

5. Displacement of people:

Another ill-effect of a multipurpose river valley project is that it displaces the local residents of that area, forcing them to leave their homes and shift elsewhere.

Chapter 7 Topic A Consequences And Control Of Environmental Degradation Short Analytical Type Questions

Question 1. What do you understand by nature-based activities?
Answer:

Nature-Based Activities:-

All sorts of human activities which are dependent on products found in nature, are involve the gathering of resources from nature.

Example

1. Gathering of wood, flowers, leaves, fruits, etc., from forests,
2. Fishing from rivers and lakes,
3. And hunting of animals from known nature-based activities. forests and
4. Cultivating crops using ancient cultivation techniques.

These resources of nature are mostly non-renewable. If the number of fish in a river is reduced due to overfishing, it cannot be replenished. The same happens in case of loss. of the fertility of the soil.

If the soil loses its natural fertility, the land becomes unsuitable for agriculture and the use of fertilizers to enhance productivity becomes useless.

Question 2. What do you mean by environmental degradation?
Answer:

Environmental Degradation:-

The overall deterioration of the quality of the environment due to human activities is known as environmental degradation. It is, therefore, the complete destruction of the balance in the ecosystem.

In this case, homeostatic mechanism cannot restore the natural balance of the environment.

The main aspects of environmental degradation are

1. Environmental pollution,
2. Deforestation,
3. Expansion of towns and cities,
4. Loss of biodiversity,
5. Loss of fertility in agricultural lands,
6. Construction of dams on rivers,
7. Desertification, etc.

Question 3. How does environmental degradation take place?
Answer:

Environmental Degradation Take Place As Follows:-

Environmental degradation takes place in several ways.

These are as follows

1. Burning fossil fuels emit huge quantities of COCO₂, SOCO_2, and other harmful gases into the atmosphere. This is the main cause of air pollution as well as environmental degradation.
2. Excessive use of chemical fertilizers, pesticides, and irrigation degraded the soil of that area and thus render it unfit for further use.
3. The construction of large dams and hydel power stations are responsible for the destruction of the ecological balance of that area. These thus induce environmental degradation.
4. Unscientific excavation of mineral resources and lifting the of huge amounts of groundwater are the principal causes of environmental degradation.
5. Chemical disaster like Bhopal Gas Tragedy (1984) and nuclear disasters like Chernobyl, Fukushima, etc., are considered as the factors leading to environmental degradation.

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Question 4. Differentiate between environmental degradation and environmental pollution.
Answer:

The differences between environmental degradation and environmental pollution are-

 

Question 5. Point out the differences between natural hazards and man-made hazards.
Answer:

The differences between natural hazards and man-made hazards are as follows-

Question 6. How do modern methods of agriculture affect the environment?
Answer:

Modern Methods Of Agriculture Affect The Environment:-

Several modern methods of agriculture, such as use of chemical fertilizers, a high-yielding variety of seeds, excessive irrigation, etc., have been undertaken to increase agricultural production.

However, these have an adverse effect on the environment. Some of these effects are discussed below-

1. Lowering the fertility level of the soil:

Repeated cultivation on a specific area of land, year after year, causes the land to lose its fertility and renders it infertile for a long time in the future.

2. Pollution:

To increase crop production, chemical fertilizers are used for cultivation. These, in turn, cause groundwater pollution. Besides these, the insecticides and pesticides which are used also pollute the soil.

On the other hand excessive use of high yeilding seeds speeds up vital genetic defects.

3. Deforestation:

To increase crop production, large forested areas are being brought under cultivation. This has resulted in rapid deforestation. As a result, many ecosystems have been destroyed.

Question 7. How has urbanization caused the degradation of the environment?
Answer:

Urbanization Caused The Degradation Of The Environment:-

Urbanisation encompasses better lifestyles and better living conditions for the people. However, environmental degradation is an eventual consequence of the process.

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The causes of environmental degradation due urbanization are

1. Reduction in the level of watertable:

An increase in population in the towns and cities has naturally increased the need for water. One of the main sources of water used on a daily basis by human beings is groundwater.

The overuse of groundwater is rapidly decreasing the level of underground watertable. This has resulted in arsenic and fluoride pollution.

2. Increased level of pollution:

Urbanisation has resulted in a rapid increase in modes of transport, factories, and other economic activities. This in turn has increased noise and air pollution in the cities.

3. Problem of drainage, sanitation, and housing:

Much of the waste disposed of in urban areas is discharged into waterbodies and into drains. This practice clogs the drainage and sanitation system and aggravates the problem of water logging.

Excessive migration of people to urban areas also causes housing problems. Unplanned urbanization leads to narrow and congested roads. This causes traffic congestion.

4. Disposal of wastes:

Indiscriminate use of plastics and other non-biodegradable materials dumped in nearby areas causes soil pollution. Dumping of garbage contaminates the groundwater and also makes the air stink.

Question 8. How do thermal power plants affect the environment?
Answer:

Thermal Power Plants Affect The Environment:-

Effects of thermal power plants on the environment are

1. Air pollution:

Thermal power plants use coal as their primary source of energy. When coal is used as fuel, it releases huge amounts of carbon dioxide, sulfur dioxide and nitrogen oxide into the atmosphere, which are extremely harmful for living organisms.

2. Increase in atmospheric temperature:

Excessive use of fossil fuels like coal, petroleum increases atmospheric temperature. This results in global warming, which, in turn, affects the earth’s climate.

3. Soil pollution:

Ash from thermal power plants are dumped on the surrounding land and renders it unfit for cultivation.

4. Acid rain:

Sulfur and nitrogen compounds emitted by thermal power plants combine with moisture in the atmosphere and cause acid rain, which has harmful effects on plants, aquatic animals, and infrastructure.

Question 9. How do hydroelectric power plants affect the environment?
Answer:

Hydroelectric Power Plants Affect The Environment:-

The effects of hydroelectric power plants on the environment are as follows

1. Disrupting the flow of rivers:

Dams built on rivers for generating hydroelectricity disrupt the flow of the rivers, and for that reason, catchment areas of the rivers are degraded continuously.

2. Destruction of forests:

When a dam is built on a river for hydroelectric power generation, large areas of surrounding forests are destroyed in order to build reservoirs to store the water.

3. Earthquakes:

The pressure created by the huge quantity of water impounding from the dam can cause earthquakes in the surrounding areas.

4. Loss in biodiversity:

Due to the loss of their habitat, the number of plants and animals in and around the river basin decreases significantly, leading to a loss in biodiversity.

Besides this, many people become homeless as the dam sites are evacuated before construction.

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Question 10. What are the effects of exploding dynamite during the construction of roads in hilly areas?
Answer:

Effects Of Exploding Dynamite During The Construction Of Roads In Hilly Areas:-

When roads are constructed in hilly regions, dynamites are used for blasting the rocks. The adverse effects of blasting are as follows

1. Noise pollution:

Dynamites explode with a lot of noise. This causes noise pollution.

2. Landslides:

The use of explosives not only causes noise pollution but also induces landslides in hilly areas.

3. Earthquakes:

The explosions can induce earthquakes in the surrounding areas.

4. Air pollution:

Dynamite explosions are responsible for the spreading of rock particles and dust in the air. This causes air pollution.

5. Destruction of the ecosystem:

Repeated explosions have an adverse effect on the flora and fauna of that region. This results in the destruction of the ecosystem of that region. This results in the destruction of the ecosystem of that area.

Question 11. Write a brief note on the Bhopal Gas Tragedy.
Answer:

Bhopal Gas Tragedy:-

On midnight of December 3, 1984, there was a leakage of poisonous MIC (thin Methyl Isocyanate) gas from Bhopal’s Union Carbide factory.

This caused one of the most terrible industrial disasters ever, which had an adverse effect on the environment. It damaged the human lungs and also burnt the cornea, killing many people and rendering others blind or crippled.

This incident came to be known as the Bhopal Gas Tragedy. People of that area are still bearing the brunt.

Effects:

1. About 4000 people and innumerable birds and animals had died.
2. About 200 thousand people were affected in some way or other.
3. Most of the affected people became crippled.
4. Many of the affected people suffered from gene mutations.
5. Pregnant women gave birth to mutated babies.

 

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Question 12. Write a brief note on the Chornobyl Disaster.
Answer:

Chornobyl Disaster:-

On April 26, 1986, an explosion occurred in a reactor in the nuclear power plant in Chornobyl, Ukraine. This incident came to be known as the Chornobyl disaster.

The operating crew were conducting some tests and had deliberately switched off the reactor’s safety systems. This resulted in the overheating of the uranium fuel rods, which exploded, and highly radioactive fallout spread over a large area of Belarus, Russia, and Ukraine.

 

 

Effects:

1. A few people died and workers of the nuclear power plant were admitted to the hospitals.
2. Thousands of people were evacuated from that area.
3. It affected the environment adversely. The surrounding land became unfit for cultivation.
4. High levels of radioactive elements affected livestock as well. Calves were born physically disabled and the meat and milk obtained from them also showed levels of radiation.
5. Researchers were of the opinion that its effects would continue for the next 100 years.

Question 13. Write a short note on Fukushima Daiichi Nuclear Disaster.
Answer:

Fukushima Daiichi Nuclear Disaster:-

On March 11, 2011, an accident took place in the Fukushima Daiichi nuclear power plant that involved five of its reactors.
This disaster was not directly related to any human activity.

Water from the sea entered the power plant due to a tsunami which had, in turn, occurred as a consequence of an earthquake. This affected five of the reactors in the power plant and the roofs of three reactors were blown off due to a hydrogen explosion.

Effects:

1. Radioactive water from the factory contaminated the seawater.
2. According to Japan’s Nuclear Safety Commission officials, the radiation released during this accident affected both air and water adversely.

Question 14. What do you know about the Minamata Disaster?
Answer:

Minamata Disaster:-

Minamata disease was first discovered in 1956. People of Minamata Bay in Japan were dying or turning disabled after consuming fish from the Bay. This is known as the Minamata Disaster.

The Chisso Corporation’s chemical factory situated in this area manufactured paint and dumped its wastes in the water of Minamata Bay. This waste contained highly toxic methylmercury which was led out in the water of Minamata Bay.

When methylmercury entered the human body through fish consumption caught from the Bay, it became fatal or caused disabilities and disorders.

Effects:

1. As a result of this contamination, 2265 people were victims of the Minamata disease. 1784 of these victims had died.
2. The water of the Minamata Bay became polluted and the ecosystem of the place was destroyed.
3. Importance has been given on controlling the levels of lead while manufacturing paint since then.

Question 15. Discuss the advantages of eco-friendly forms of energy.
Answer:

Advantages Of Eco-Friendly Forms Of Energy:-

The advantages of environment-friendly forms of energy include

1. The production of this form of energy does not cause pollution.
2. The sources for generating this type of energy (the sun, wind, etc.) are inexhaustible.
3. The initial establishment cost is high, but in the long run the production cost is negligible.
4. The generation of electricity through this method can prevent the misuse of energy resources of the earth.

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Question 16. What is Earth Summit?
Answer:

Earth Summit:-

Earth Summit is an international conference on environment and development which was held in Rio de Janeiro, Brazil in the year of 1992. It is also known as the United Nations Conference on Environment and Development (UNCED) or Rio Summit.

More than thirty thousand people from 178 countries participated in this conference. The famous action plan for the 21st century, Agenda 21, was the product of this Earth Summit.

Some resolutions regarding the environment and development were adopted in this conference.

Question 17. What is sustainable development?
Answer:

Sustainable Development:-

Sustainable development refers to development aimed at the optimum use of natural resources in the present scenario so that development can go unhampered while also preserving the reserves of nature and the potential of human society to develop, for future use.

The objectives of sustainable development are as follows

1. Using the available resources in multiple ways.
2. Judicious use of non- renewable resources.
3. Using technology to optimise the use of available resources.
4. Preventing the misuse of natural resources.

Question 18. How did the idea of sustainable development emerge?
Answer:

Idea Of Sustainable Development Emerge:-

Population explosion, human activities, exploitation of resources for their increasing and uncontrolled demand for comfort has caused degradation of the environment to an alarming extent.

This has hugely depleted the resources and put the very existence of future generations at risk. It is the acknowledgment of this extreme situation that led to the idea of sustainable development being proposed, legislated, and implemented worldwide.

Question 19. What is desertification?
Answer:

Desertification:-

A type of land degradation, where certain areas of land become arid and slowly take the form of a desert, is known as desertification.

Causes:

The causes of desertification are

1. Excessive farming in the desert margins,
2. Indiscriminate felling of trees in the semi-arid regions,
3. Overgrazing by animals,
4. Exploitation of groundwater and
5. Excessive use of chemical fertilizers and pesticides.

Effects:

The effects of desertification are

1. Salinity of the soil increases,
2. Change in climate occurs,
3. Vegetation cover reduces,
4. The growth of cactus-like plants is prominent,
5. Droughts occur frequently.

Question 20. What is Jhum cultivation? What are its impacts on the environment?
Answer:

Jhum cultivation:

Jhum cultivation is one of the ancient practices used for agriculture. It is the process of growing crops on a particular land surface by clearing the existing trees and vegetation cover on it, and burning them thereafter.

After a few years, when the land loses move on to another patch of land and repeat this its fertility, the farmers abandon the land and process. This form of cultivation is also known as shifting agriculture.

Impact of Jhum Cultivation on the Environment:

1. This form of cultivation requires the clearing of forest areas. This affects the environment adversely and also results in the loss of several rare species of flora and fauna.
2. It results in rapid soil erosion.
3. Jhum cultivation creates an imbalance in the existing ecosystems and the burning of trees causes severe air pollution.

Question 21. What is the greenhouse effect?
Answer:

Greenhouse Effect:-

In colder countries, crops are often grown in glass houses to keep them warm.

 

 

These are known as greenhouses. Shortwave radiations from the sun enter through the glass, but the long-wave radiations that are reflected back from the earth are stopped by the glass walls.

As a result, the plants inside the greenhouse remain warm and grow well. French mathematician and physicist Joseph Fourier had compared the earth’s atmosphere to a greenhouse.

The sun’s rays enter the earth as shortwave radiations, but when they are reflected back by the earth as long-wave radiations, different gases, dust particles, water vapour, etc., present in the atmosphere prevent them from leaving.

Instead, these rays are sent back to the earth. This, in turn, increases the temperature of the earth’s surface. This is known as the greenhouse effect and the gases causing it are known as greenhouse gases.

Question 22. What are the consequences of the greenhouse effect?
Answer:

Consequences Of The Greenhouse Effect:-

The consequences of the greenhouse effect are as follows-

1. The average temperature of the earth is gradually rising.
2. The climate is changing.
3. Glaciers are melting at an alarming rate.
4. The sea level is gradually rising.
5. There is a decrease in agricultural production as well as in the supply of drinking water.
6. Loss of biodiversity is seen worldwide.

Question 23. Write a short note on Phailin.
Answer:

Phailin:-

The 260 km/hr cyclone that originated in the Bay of Bengal in 2013 was named Phailin. It is considered to be the second most powerful cyclone that has hit India in recent times.

Phailin first originated as a tropical depression on October 4, 2013, in the Gulf of Thailand. On October 7, it reached the Andaman and Nicobar Islands and on October 12, it wreaked havoc in and around Gopalpur in Odisha.

This cyclone prompted India’s biggest evacuation in 23 years with more than 5 lakh people moving up from the coastline in Odisha and Andhra Pradesh to safer places. Phailin damaged agricultural crops and caused a huge loss of property.

Question 24. Write the differences between environmental hazards and environmental disasters.
Answer:

Differences between environmental hazard and environmental disaster are

 

Question 25. Why do fish at times and other aquatic creatures die in ponds?
Answer:

Fish At Times And Other Aquatic Creatures Die In Ponds:-

When the water in a pond gets polluted, the fish living in it die. Ponds can get polluted due to several reasons

1. Eutrophication:

The process of eutrophication reduces the amount of oxygen present in the water, resulting in the death of fish living in the pond.

2. Dumping of wastes:

Often in towns or villages, nearby ponds are used as a place to dump the garbage. This causes pollution and reduces the depth of the ponds as well, thereby resulting in the death of aquatic life.

3. Water from factories:

Often dirty and toxic water discharged from factories flow directly into nearby ponds, causing an acute level of water pollution. This destroys the eco-system of the pond killing aquatic creatures.

4. Chemical fertilizers and pesticides:

Excessive use of chemical fertilizers and pesticides in agriculture contaminates the nearby waterbodies when the soil mixed with these chemicals enters the waterbodies as a part of surface run-off.

 

Chapter 7 Topic A Consequences And Control Of Environmental Degradation Short Answer Type Questions

Question 1. What do you understand by the nature-based activities of human beings?
Answer:

Nature-Based Activities Of Human Beings:-

Nature-based activities are those in which human beings directly use natural resources as the basis for their economic activities. These are classified as primary economic activities.

Example- hunting, fishing, and primitive agriculture.

Question 2. What are technology-based activities?
Answer:

Technology-Based Activities:-

When the resources obtained from primary economic activities are used to create and develop goods through the use of technology, they are known as technology-based activities.

Example-Generation of electricity from coal.

Question 3. What do you mean by the social activities of human beings?
Answer:

Social Activities Of Human Beings:-

Social activities are those activities that provide human beings with helpful services.

Examples- Banking, insurance, education, healthcare, transport, etc.

Question 4. Name some activities which are considered to be social services.
Answer:

Some activities which are considered as social services are healthcare, teaching, banking, insurance, etc.

Question 5. What is meant by homeostatic mechanism?
Answer:

Homeostatic Mechanism:-

The physical and biotic processes of nature have a self-regulatory style of working. Any change or damage caused by them to the environment is naturally restored, compensated or adjusted. This is called homeostatic mechanism.

Question 6. In the initial stages of civilization, how were human beings totally dependent on nature?
Answer:

In the early years of civilization, human beings were hunters and gatherers, collecting fruits from forests and hunting animals that lived there. Early man lived as a part of nature, without degrading or causing damage to the environment.

Question 7. How did the invention of the wheel increase the pace of evolution?
Answer:

Invention Of The Wheel Increase The Pace Of Evolution:-

With the invention of the ‘wheel’, the pace of human life increased. The usage of vehicles for transportation gained popularity. Also, from this phase, the man started exploiting nature for his own interests.

The invention of the wheel changed man’s relationship with nature. However, the human population was very low at that time and human activities did not cause any significant harm to the environment.

Question 8. What is meant by environmental pollution?
Answer:

Environmental Pollution:-

Soil, air and water are integral parts of our environment. When these components become contaminated or degraded due to natural or human activities, it causes environmental pollution. This, in turn, has adverse effects on living organisms.

Question 9. What are multipurpose river valley projects?
Answer:

Multipurpose River Valley Projects:-

Projects are undertaken to build large dams on various rivers to store the river water and use it for diverse purposes. These projects are known as multipurpose river valley projects.

Example- Damodar Valley Corporation.

Question 10. What are the main objectives of the multipurpose river valley projects?
Answer:

Main Objectives Of The Multipurpose River Valley Projects:-

The main objectives of these projects are

1. Irrigation,
2. Generation of hydro-electricity,
3. Flood control,
4. Pisciculture,
5. Tourism,
6. Transportation,
7. Distribution of drinking water,
8. Prevention of soil erosion,
9. Construction of roadways, railways, and bridges, etc.

Question 11. The main causes of environmental degradation are lack of education and poverty. Explain.
Answer:

The main causes of environmental degradation are lack of education and poverty:-

Illiteracy and poverty are the two main reasons why people exploit the environment. Collecting of wood from forests, grazing cattle, unplanned exploitation of mineral resources, lifting of excessive groundwater, etc., have adverse effects on the environment.

Again, poverty and lack of awareness are also responsible for the uncontrolled growth of the population. It is mainly through education that people will become aware of the importance of keeping the environment healthy and take up the path of sustainable development.

Question 12. Only environmental reform movements can protect the environment. Justify.
Answer:

Only environmental reform movements can protect the environment:-

Various movements have been initiated over the years in order to save the environment from being affected adversely.

Example

1. No trees were cut for about 10 years in the Himalayan region due to the Chipko Movement that was launched in Uttarakhand’s This region. the movement had a global impact.
2. Due to the Silent Valley Movement, the evergreen forest in the Palakkad district of Kerala has been declared a National Forest.
3. Narmada Bachao Andolan, Anti-Tehri Dam Movement, etc., have been equally effective in protecting the environment.

Question 13. How did the Bhopal Gas Tragedy which caused the death of about 4000 people and numerous birds and animals occur?
Answer:

On midnight of December 3, 1984, a tank of MIC (Methyl Isocyanate) gas exploded in Bhopal’s Union Carbide Factory, causing one of the most terrible industrial disasters ever.

This gas is used to produce pesticides. If not stored in a cold place and if it comes in contact with water, the gas undergoes a chemical reaction. This reaction between water and MIC was the main cause of the accident.

Question 14. What do you understand by eco-friendly forms of energy?
Answer:

Eco-Friendly Forms Of Energy:-

Environment-friendly or eco-friendly forms of energy are those that do not harm or pollute the environment when they are produced or used. These include solar energy, wind energy, tidal energy, etc.

These forms of energy are also known as green energy or sustainable energy or renewable energy.

Question 15. What is meant by biodiversity?
Answer:

Biodiversity:-

Biodiversity means the variety of living organisms, both flora and fauna, existing in a particular habitat. The Earth Summit. organised in 1992 put forth a comprehensive idea of biodiversity.

Question 16. Why is the idea of sustainable development gaining importance?
Answer:

The idea of sustainable development is gaining importance because

1. Wastage of resources can be checked;
2. The use of eco-friendly technology will increase;
3. Poverty and illiteracy will decrease;
4. Environmental pollution will be checked.

All these help in keeping the environment healthy. Hence, sustainable development is gaining importance at present.

Question 17. What do you mean by environment?
Answer:

Environment:-

The term environment indicates an organism’s surroundings including both living and non-living things, where plants and animals can co-exist.

Thus, the environment not only includes human beings but also other living and non-living things around them, each of which are co-related.

Question 18. What do you mean by physical environment?
Answer:

Physical Environment:-

Physical environment is equated with nature, which includes the physical components of the earth namely land, air, water, soil, etc. Human activities are not included in this environment.

Question 19. What is meant by economic environment?
Answer:

Economic Environment:-

Economic environment is the sum of those factors which directly or indirectly influence economic activity in an area. Agriculture and industry, are examples of the economic environment.

Question 20. What is meant by ecosystem?
Answer:

Ecosystem:-

A community of organisms living in association with the non-living components of the environment in a particular area, interacting as a system, forming an ecosystem. It may be as small as a cowshed or a tree.

The largest unit of an ecosystem is the entire biosphere. A.G. Tansley (1935) had first used the term ‘ecosystem.

 

Chapter 7 Topic A Consequences And Control Of Environmental Degradation Multiple Choice Questions Choose the correct option

Question 1. The activity of manufacturing goods is a-

1. Self-service
2. Social service
3. Technology-based activity
4. Nature-based activity

Answer: 3. Technology-based activity

Question 2. The overall deterioration of the quality of the environment is known as-

1. Environmental pollution
2. Homeostatic mechanism
3. Environmental management
4. Environmental degradation

Answer: 4. Environmental degradation

Question 3. Which of the following is associated with environmental degradation?

1. Construction of reservoir
2. Loss of biodiversity
3. Smog
4. Bad odor from the fish market

Answer: 2. Loss of biodiversity

Question 4. The ‘Phailin’ had hit-

1. Assam
2. Odisha
3. Bihar
4. Maharashtra

Answer: 2. Odisha

Question 5. The destructive power of ‘Aila’ was felt in-

1. Jharkhand
2. West Bengal
3. Kerala
4. Gujarat

Answer: 2. West Bengal

Question 6. Arsenic pollution is a part of

1. Soil pollution
2. Groundwater pollution
3. Air pollution
4. Noise pollution

Answer: 2. Groundwater pollution

Question 7. Chemical fertilizers and pesticides pollute the-

1. Soil
2. Water
3. Air
4. Soil and water both

Answer: 4. Soil and water both

Question 8. The following is emitted due to the burning of fossil fuels-

1. H₂
2. CO₂
3. CH₄
4. bO₂

Answer: 2. CO₂

Question 9. Bhopal Gas Tragedy occurred in-

1. 1984
2. 1974
3. 1994
4. 2008

Answer: 1. 1984

Question 10. Chornobyl nuclear disaster occurred in-

1. 1966
2. 1976
3. 1986
4. 1996

Answer: 3. 1986

Question 11. The Fukushima Daiichi accident occurred in-

1. 1981
2. 1991
3. 2001
4. 2011

Answer: 4. 2011

Question 12. Environment-friendly energy is-

1. Thermal energy
2. Nuclear energy
3. Solar energy
4. None of these

Answer: 3. Solar energy

WBBSE Class 8 Geography Chapter 7

Question 13. World Environment Day is observed on

1. 5 June
2. 5 September
3. 5 March
4. 2 October

Answer: 1. 5 June

Question 14. The following may happen as a result of excessive deforestation-

1. Soil erosion and flood
2. Reduction of biodiversity
3. Desertification
4. All of the above

Answer: 4. All of the above

Question 15. Which of the following is directly responsible for the climatic change?

1. Indiscriminate use of resources
2. Deforestation
3. Unplanned development
4. Increase in temperature

Answer: 4. Increase in temperature

 

Chapter 7 Topic A Consequences And Control Of Environmental Degradation Very Short Answer Type Questions Fill In The Blanks

Question 1. Computer manufacturing is a _______-based activity.
Answer: Technology

Question 2. Environmental pollution accelerates environmental _______.
Answer: Degradation

Question 3. Unscientific agricultural methods reduce _______ of soil.
Answer: Fertility

WBBSE Class 8 Geography Chapter 7

Question 4. The full form of MIC gas is _______.
Answer: Methyl isocyanate

Question 5. Almost _______ people lost their lives in the Bhopal Gas Tragedy.
Answer: 4000

Question 6. The United Nations Conference on Environment and Development called the _______ was held in Rio de Janeiro, Brazil in 1992.
Answer: Earth Summit

Question 7. _______ is one of the primary factors responsible for increasing desertification of land.
Answer: Deforestation

 

Match The Columns

1.

Answer: 1. C, 2. A, 3. B, 4. E, 5. D

2.

Answer: 1. D, 2. E, 3. A, 4. B, 5. C

 

Answer In One Or Two Words

Question 1. Give an example of nature-based activity.
Answer: Agriculture.

Question 2. Give an example of technology-based activity.
Answer: Computer manufacturing.

Question 3. Name the system which compensates any disturbance caused to any part of the environment and thus maintains ecological balance.
Answer: Homeostatic mechanism.

Question 4. Give an example of environmental degradation caused by man.
Answer: Industrial toxic wastes are discharged into nearby waterbodies.

Question 5. What is the name of the type of cultivation that causes environmental degradation in India?
Answer: Jhum cultivation.

Question 6. Give an example of an earthquake in India caused due to the pressure of the reservoir of a dam.
Answer: Koyna earthquake, Maharashtra, 1967.

Question 7. What is the full form of MIC?
Answer: Methyl Isocyanate.

WBBSE Class 8 Geography Chapter 7

Question 8. What primarily caused the mishap in Fukushima, Japan?
Answer: Tsunami.

Question 9. Name eco-friendly non-conventional energy.
Answer: Solar energy.

Question 10. Which country hosted the ‘Earth Summit’ of 1992?
Answer: Brazil.

Question 11. Give an example of a natural disaster.
Answer: Tsunami.