Class 11 Environment Chapter 6 Social Issues and Environment Question Answer to each chapter is provided in the list so that you can easily browse through different chapters Assam Board HS 1st Year Environmental Studies Chapter 6 Social Issues and Environment Question Answer.
Class 11 Environment Chapter 6 Social Issues and Environment
Also, you can read the SCERT book online in these sections Solutions by Expert Teachers as per SCERT (CBSE) Book guidelines. These solutions are part of SCERT All Subject Solutions. Here we have given Assam Board Class 11 Environment Chapter 6 Social Issues and Environment Notes for All Subjects, You can practice these here.
Social Issues and Environment
UNIT – 6
ENVIRONMENTAL STUDIES
Textual Questions and Answers
1. What do mean by sustainable development? 2014, 16
Ans: Sustainable development is defined as meeting the needs of present without compromising the ability of further generations to meet their own needs:
2. What are renewable and non-renewable energy resources? Give examples.
Ans: Renewable energy resources: These energy resources are generated continuously in nature and are in-exhaustible. For example solar energy, wind energy, hydropower energy, geothermal energy, ocean thermal energy, tidal energy, wood, biomass energy, bio-fuels, hydrogen etc. They can be used again and again. They are the non-conventional or alternative sources of energy.
Non-renewable energy resources: These energy sources, accumulated in nature, have been in use for a long time and are exhaustible. Once these sources are finished, they can not be replenished quickly. For cuample fossil fuels (coal, petroleum, natural gas), nuclear fuels like tranium, thorium etc. These are used conventionally to meet the energy demands of human society.
3. What is energy conservation? Mention some measures for energy conservations.
Ans: As stated above, development in every sector depends largely etgy. The rate of energy consumption today is a nation has direct correlation with economic growth and prosperity. The stage of development is well reflected by the per capita energy consumption of a country. The energy crisis has led to the formulation of an energy policy framework within which the rate of growth and pattern of an energy consumption can be regulated and energy conservation strategies are to be adopted.
Energy conservation refers to efforts made to reduce energy consumption, can be regulated and energy conservation strategies are to be adopted. Energy conservation refers to efforts made to reduce energy consumption Energy conservation can be achieved through efficient energy use, in conjunction with decreased energy consumption and or reduced consumption from conventional energy sources. Energy conservation can result in increased financial capital, environmental quality, national security, personal security and human comfort. Individuals and organizations that are direct consumers of energy choose to conserve energy to reduce energy costs and promote economic security. Industrial and commercial users can increase energy use efficiency to maximize profit. Energy, which saves money, and at the same time saves the earth. When we decrease the amount of energy we automatically make efforts to reduce global warming.
The following measures for energy conservation can be adopted as initial steps
(a) Shiftgig from the use of fossil fuels and non renewable energy resources such as petroleum, coal, natural gas, uranium etc to renewable energy resources such as solar energy, wind energy, biogas etc.
(b) More technological innovation contributing efficient energy saving
(c) Unnecessary use of electricity should be prohibited. Street lights should be suntched off early in the morning
(d) Domestic consumers can curtail energy consumption on many household goods.
(e) Industries should develop a mechanism for judicious use of raw materials for their energy needs.
4. What is rain water harvesting? What are the objectives of rain waer harvesting?
Ans: Rainwater harvesting is a technique of collection of rainwater from paved or Gl. corrugated roofs and paved courtyard of houses. It also involves increasing the recharge of ground water by capturing and storing rainwater. This is done by constructing special water harvesting structures like dug wells, percolation pits, lagoons, check dams etc. Rainwater harvesting is now being increasingly used for meeting domestic water needs in the rural as well as urban areas, particularly during the dry period.
Rainwater harvesting has the following objectives:
(i) To reduce run off loss
(ii) To meet increasing demands of water
(iii) To reduce pressure on ground water resource
(iv) To raise ground water table by the process of recharging
5. Describe the different steps involved in rain water harvesting.
Ans: Rainwater harvesting system consists of four basic elements:
(i) A collection area or a catchment
(ii) A conveyance system
(iii) Storage facilities (water tank)
(iv) Delivery or distribution system.
(i) Collection area or catchments: Catchments determine the quantity and to some extent the quality of water that enters the storage tank, Catchments are of two types
(a) Roof: The roof of a house of a building is the most prominent catchment of water for domestic purposes. An impermeable roof will yield high runoff of good quality water for all household purposes. There are several types of roof such an concrete roofs, GI Sheets, asbestos, tiles etc.
(b) Ground catchments: A ground water catchment has a lower runoff coefficient than a hard roof. Since it is usually much larger, it can yield a high runoff. Ground water is prone to contamination from many sources including human and other animal excreta, rotten vegetation etc: The water from these catchment is not usually of high quality. However, it can be used for secondary purposes like gardening, washing etc.
(ii) Conveyance system: The water collected in the catchment must be stored in the storage tank by some means. The system, which delivers the collected water to the storage tank, is the conveyance system. The conveyance is usually done by way of guttering. Other systems such as roof slide or ground slide can be used, but these are less popular for rainwater harvesting as they either spill water or may be contaminated.
(iii) Storage tank: The water collected is ultimately stored in storage tanks. They should be constructed of an inert material such as reinforced concrete, fibre glasses or stainless steel. The storage tank may be constructed as a part of the catchments or may be built as a separate unit. It should include the following as a minimum requirement
(a) A solid cover
(b) A course inlet filter
(c) An overflow pipe
(d) A manhole or drain to facilitate cleaning
(iv) Delivery system: This is an extension system connected to the storage tank. Through this system water is distributed to the households, to the cultivable lands or to the small scale industries. A filtering system should be involved in the process to prevent contamination of water. All catchments surfaces, conveyance systems, storage thanks and delivery systems should be made of non-toxic, non-corrosive materials, Painted surfaces should be avoided it possible, No lead, chromium or zine based paints should be used.
6. What are the advantages of rain water harvesting?
Ans: The advantages of rain water harvesting:
(i) It provides a source of water at the point where it is needed.
(ii) It involves little cost and every household can easily accommodate the simple mechanism required for recycling rainwater
(iii) Rainwater is free from the contamination of fluoride, arsenic, iron ete.
(iv) Recycling of rainwater for domestic and other uses of significantly reduce the pressure on ground water as ground water depletion has become a serious problem in many cities of the world.
(v) it provides an essential reserve in times of emergency or breakdown of public water supply systems.
(vi) The technologies are simple and common people can easily be trained to build one storage tank to rainwater with a minimum cost
7. How health may be affected by the environment?
Ans: According to World Health Organization (WHO) health is state of complete physical, mental and social well being and not merely the absence of disease or infirmity”. Human health is effected by the environment, Many factors like nutritional, chemical, physical, biological, psychological, poor living conditions etc are correlated, with human health.
Access to safe drinking water is essential to health, a basic human right and a component of water, sanitation and hygiene for health and development has been reflected in the outcomes of a series of international and national policy forums.
More than 80% diseases in India are water related, and include typhoid, cholera, hepatitis,polio, gastro-enteritis, amoebiasis, giardiasis etc. Over four lakh children die annually in india due to water borne diseases. The most common and widespread health risk associated with drinking water is microbial contamination. Many toxic chemicals, pesticides, heavy metals (mercury, cadmium, lead etc) are released into the water bodies and soil. These may ultimately enter the human body through the food chain causing adverse impacts on health Industries and transportation systems also release a number of gases into the atmosphere. Some of these gases (c.g. sulphur dioxide, carbon monoxide, nitrous oxide, hydrocarbons and suspended particulate matter)
can cause different health effects at different levels (see units). Solid waste has the potential to degrade the air, water and the soil. There are potential risks to health and to the environment. Sometimes improper housing with poor hygienic condition may cause serious health effects. This is generally seen among the slum dwellers in urban areas. Illiteracy and lack of awareness about their health and environment, poverty and large family size, poor drainage and sanitation system and absence of proper medical facilities are the main reasons for the poor health conditions of the people.
8. What are disasters ?
Ans: Disaster is a catastrophic situation disrupting the normal life creating chaos, loss of lives and property, degrading the environment necessitating large scale rescue, evacuation and relief efforts to bring life and business back to normal.
Disasters are broadly categorized as:
(a) Natural Disasters: Disasters resulting from natural phenomena like earthquake, volcanic eruption, storm surges, cyclones, floods, landslides, forest fires, tsunamis, droughts, famines etc are under this category.
(b) Artificial disasters: Disasters arising out of human activities such as armed conflicts sabotage, industrial accidents, oil and gas structural collapses, bomb blasts, road accidents etc are under the category.
9. What do you mean by disaster management? What management strategy you can adopt during flood?
Ans: Geological processes like earthquakes, volcanoes, floods and andfladies are normal natural events which have resulted in the formation of the earth that we have today. They are, however, disastrous in their impacts when they affect human settlements. Human societies have witnessed a large number of such natural hazards in different parts of the world and have tried to learn to control these processes, to some extent.
Following are the management of flood control:
(i) The construction of embankments on lower beaches of rivers to divert flood water is one of the major methods of flood control.
(ii) One of an important method of flood control is reforestation.
(iii) Construction of spars which control both flood and bank erosion is one of the most mentionable method of flood control.
(iv) To provide sufficient protection against flood dams help very friendly. River dams is also a method of control.
(v) By restoring vegetation and institution efficient methods of soil management and conservation flood can be control,
10. Population explosion is the root cause of environmental degradation- Explain the statement.
Ans: The population in our country is the single most serious problem being faced by us. It is the mother problem which breeds many other problems. Due to population explosion, the per capita land area declined from 0.82 hectare in 1951 to 0.48 hectare in 1981. The ever increasing growth of population, low man-land ratio and poverty have put a pressure on our resources and environment. This has led to the destruction of forests, encroachment upon the reserve forests and migration to the big cities in search of livelihood. Due to congestion in cities the quality of air and water is greatly affected becoming unfit for human consumption. Migration of rural people mostly wage earners to the urban areas led to the formation of slums. The slums areas have no civic amenities of water supply, drainage, roads, transport etc. That leads to many social problems. Slum dwellers face environmental, social, economic, health, educational and cultural problems.
So, it is apparent that sustainable development of a nation is possible only with preservation of the environment and preservation of environment is only possible if population growth is brought under control.
VERY SHORT TYPES QUESTION & ANSWER MARKS
1. Which was the first country to enact a Wild Life Protection Act.”?
Ans: India was probably the first country to enact a “Wild Life Protection Act.
2. When was the Wild Birds and Animals Protection Act repealed?
Ans: The Wild Birds and Animals Protection Act was repealed in 1912.
3. When and where was the United Nations Conference on Human Development held?
Ans:The United Nations Conference on Human Development was held at Stockholm (Sweden) in June 1972.
4. What is the aim of the Wildlife Protection Act?
Ans: The Wildlife Protection Act aims at providing protection to wild animals, birds and plants.
5. When did the Parliament pass Water (Prevention and Control of Pollution) Act and from when did it become effective?
Ans: The parliament passed the Water (Prevention and Control of Pollution) Act in 1973 which became effective from 23rd March 1974.
6. What is the full form of CB PCWP?
Ans: The Central Board for Preservation and Control of Water Pollution.
7. Who look after the matters related with air pollution?
Ans: CBPCWP look after the matter related with air pollution.
8. When was the Air (Prevention and Control of Pollution) Act 1981 amended?
Ans: The Air (Prevention and Control of Pollution) Act 1981 was amended in 1987.
9. What power was given to CPCB after changing its name from CBPCWP?
Ans: The Boards were given powers to close or stop supply of water and electricity to offending establishments.
10. What was the aim of the Motor Vehicles Act, 1988?
Ans: The main aim of the Motor Vehicle Act, 1988 was at issue of permits, rather than controlling the emissions.
11. Mention one of the factors that disturb the balance of nature.
Ans: Population explosion.
12. Give one consequence of modern development of science and medical sciences.
Ans : Life expectancy of man has increased as a result of modern development of science and medical science.
13. Mention one consequence of deforestation.
Ans: Global warming.
14. Name some instances of human tragedy caused by environmental pollution.
Ans: Minamata Disease, Bhopal Gas disaster and Chernobyl nuclear tragedy.
15. How is the behaviour of the people of the developed countries towards the environment?
Ans: The behaviour of the people of the developed countries towards the environment has always been unethical.
SHORT & LONG TYPES QUESTION & ANSWER MARKS:
1. What is meant by environmental ethics?
Ans: Environmental ethics means our proper behaviour towards the environment. Environmental ethics also include the laws and regulations enacted by the government for preservation of biosphere. So, we can say that the most important point of environmental ethics is for conserving biodiversity.
2. “We should not destruct forest for human settlement or establishment of industries.”- Justify the statement.
Ans: Due to the high rate of population increase the forests have been cleared to find new areas for settlements and establishment of industries. This has resulted in increasing ‘Green House Gases’ and this has caused “Global Warming and other manifestations associated with it. Again forests also provide us food, medicines and other products of commercial importance. So, destruction of forests itself is not ethical to our environment. Forests maintain the atmospheric balance. Hence, to maintain our atmosphere in balance we must stop destruction of forest and we should adopt the policy of afforestation.
3. How we can conserve biodiversity?
Ans: The most important point of environmental ethics is for Lenserving bindeversity. The following assertions based on the intrinsic value of species are important for conservation of biodiversity and protecting the ecosystems.
(i) Each species of plants and animals has a right to exist. Each species has values for its own sake, an intrinsic value unrelated to human needs. So, for our need and comfort we should not disturb them.
(ii) All species are interdependent. The loss of one species may have for reaching consequences for other members of the community. Killing of animals far the sake of sport or meat disturbs the whole food chain and ultimately adversely affects that ecosystem.
(iii) Human beings must limit their greed for self prestige and power and learn to live within the same ecological limitations as the other species do.
(iv) People must take responsibility for their actions. If some organisations individuals are responsible for polluting the environment, they must take corrective measures.
(v) People have a responsibility for future generation. In all of our actions we must think of keeping the planet clean and should not waste limited resources at least those resources which are non-renewable.
(vi) A respect for human life and ethnic diversity is compatible with respect for biodiversity.
(vii) We must learn aesthetic values from nature. The protection and presentation of our diversity only will provide us life supporting system as well as opportunities for economic upliftment.
(viii) Biodiversity must be protected to determine the origin of life.
4. Do you believe that plants and animals have right to exist?
Ans: Each species of plants and animals has a right to exist. Each species has values for its own sake, an intrinsic value unrelated to human needs. All species are interdependent. The loss of one species may have far reaching consequences for other members of the community. Killing of animals for the sake of sport or meat disturbs the whole food chain and ultimately adversely affects that ecosystem. So, for our need and comfort we should not disturb them.
5. Name some Acts, which were passed by the British governments.
Ans: Some notable Acts passed by the British governments were:
(i) Indian Fisheries Act, 1897
(ii) The Indian Ports Act, 1907
(iii) Bengal Smoke Nuisance Act, 1905
(iv) The Motor Vehicle Act, 1938.
(v) The Forest Act XVI, 1927.
6. Write short notes on :
(a) Wildlife (Protection) Act, 1972
Ans: The salient features of ‘Wildlife (Protection) Act, 1972 are as follows:
(i) It provides greater protection to wildlife and enhance the punishment for violations
(ii) It also brings about a complete prohibition of hunting of all specifie wildlife.
(iii) No hunting and trafficking licences are to be issued and existing licences are to be cancelled.
(iv) Commercial felling and exploitation of wildlife in sanctuaries have been banned.
(b) Water (Prevention and Control of Pollution) Act, 1974
Ans: The following actions were taken by the government after the “Water Protection and Control of Pollution Act 1974” was passed.
(i) This Act banned throwing or adding substances to sources of water that can pollute it and also prevented any action which may affect the natural flow of water.
(ii) It also provided for establishment of laboratories in the states to examine specimen of water for detecting pollution.
(iii) The state boards on the basis of the reports of the laboratories can file cases against organisations/ individuals violating the provisions of the Act.
(c) The Environment (Protection) Act, 1986
Ans: (i) Planning and execution of a nationwide programme for prevention, control and abatement of environmental pollution.
(ii) Laying down standards for the quality of environment, or emission or discharge of environmental pollutants.
(iii) Carrying out or sponsoring investigations and research relating to problems of environmental pollution or collection and determination of information or preparation of manual codes relating to the prevention, control and abatement of environmental pollution.
(d) The Motor Vehicle Act, 1988.
Ans: The salient features of the Motor Vehicles Act 1988 are as follows:
(a) From 01.10.89 every motor vehicle shall comply with the following emission standards:
(i) Idling emission limit for four-wheeler patrol driven vehicles shall not exceed 3 per cent by volume.
(ii) Idling emission limit for two-wheelers and three-wheelers petrol driven vehicles shall not exceed 4.5 percent by volume.
(iii) Some density for diesel driven vehicles shall be 65 HSU.
(b) Every transport vehicle to have a certificate of fitness.
(i) For violation of emission standards, penalty for first offence is Rs. 1,000 and for the subsequent offences is Rs. 2000 each. The offence is non-compoundable and only the court of law will impose penalty.
7. What constitutional provisions have been provided for protection of environment?
Ans: For the purpose of protection of environment some constitutional provisions have been provided.
These provisions are :
(i) The state shall endeavour to protect and improve the environment and to safeguard the forests and wildlife of the country. (Article 48 A)
(ii) “If shall be the duty of every citizen of India to protect and improve the natural environment including forests, lakes, rivers and wildlife and to have compassion for living creatures.
8. Why has it become necessary to enact laws on environment?
Ans: After independence of India, the real awareness about environmental protection at global level was recognised at the United Nations Conference on Human Development at Stockholm (Sweden) in June 1972. This conference followed a series of actions including enactments of laws. For the purpose of protection and improvement of biosphere and human environment, it has become necessary to enact laws on environment.
9. What are the salient features of ‘Wildlife (Protection) Act,1972.
Ans: The salient features of ‘Wildlife (Protection) Act, 1972 are a follows:
(i) It provides greater protection to wildlife and enhance the punishment for violations.
(ii) It also brings about a complete prohibition of hunting of all specified wildlife.
(iii) No hunting and trafficking licences are to be issued and existing licences are to be cancelled.
(iv) Commercial felling and exploitation of wildlife in sanctuaries have been banned.
(v) Stocks of wildlife article held by dealers are to be verified and identity stamps placed on each.
(vi) A definite time table is proposed for the dealers to get rid of their stocks, after which there can be no trade in wildlife.
(vii) It also banned trade in imported ivory and its products and transportation of wildlife or products without permission.
10. What follow up actions were taken by the government after the ‘Water Protection and Control of Pollution Act 1974 was passed?
Ans: The following actions were taken by the government after the Water Protection and Control of Pollution Act 1974″ was passed.
(i) This Act banned throwing or adding substances to sources of water that can pollute it and also prevented any action which may affect the natural flow of water.
(ii) It also provided for establishment of laboratories in the states to examine specimen of water for detecting pollution.
(iii) The state boards on the basis of the reports of the laboratories can file cases against organisations/individuals violating the provisions of the Act.
(iv) The punishment for violation includes 6 year imprisonment and a fine of Rs. 5,000,.
11. What are the important points of “The Environmental Protection Act 1986′
Ans: The Act provides general powers to the central government to take all necessary measures for preventing, controlling and abating the environmental pollution.
The Act empowers the central government to take the following
(i) Planning and execution of a nationwide programme for prevention,
steps:
control and abatement of environmental pollution.
(ii) Laying down standards for the quality of environment, or emission or discharge of environmental pollutants.
(iii) Carrying out or sponsoring investigations and research relating to problems of environmental pollution or collection and determination of information or preparation of manual codes relating to the prevention, control and abatement of environmental pollution.
12. What are the salient features of the Motor Vehicles Act 1988
Ans: The salient features of the Motor Vehicles Act 1988 are as follows:
(a) From 01.10.89 every motor vehicle shall comply with the following emission standards:
(i) Idling emission limit for four-wheeler patrol driven vehicles shall not exceed 3 per cent by volume.
(ii) Idling emission limit for two-wheelers and three-wheelers petrol” driven vehicles shall not exceed 4.5 percent by volume.
(iii) Some density for diesel driven vehicles shall be 65 HSU.
(b) Every transport vehicle to have a certificate of fitness.
(i) For violation of emission standards, penalty for first offence is Rs. 1,000 and for the subsequent offences is Rs. 2000 each. The offence is non-compoundable and only the court of law will impose penalty.
13. What is acid rain and how is it form? How can you controlid rain?
Ans: When rain water contains acid, it in called acid rain, Rain water dissolved pollutants like oxide of sulphur nitrogen and carbon in the air and brings them down in the form of acid rain. The amount of pollutants determines the power of acid content in rain water. Pollutants remain in atmosphere in gaseous form and they are driven away from place to place. Due to the movement of the pollutants acid rain can occur at different places. Acid rain is called ‘lake killers. This is due to the fact that acid rain is one of the major causes of the death of lakes. Acid rain affects trees and plants and aquatic animals. Acid rain destroys some of the essential nutrients of soil and thus affects productivity of soil. Acid rain has destroyed some forests in Canada, Germany and the USA.
About 50000 lakes in Canada have died because of acid rain. Acid rain also effects human life. But the amount of effect has not yet been determined. It also affects buildings and other structures. The Taj Mahal has lost its original glaze because of sulphur di oxide emitted by Mathura Oil Refinery. According to studies conducted by Bhabha Atomic Research Centre and World Meteorological Organization the effect of acid rain in Indian cities is not yet fearful.Acid rain can be controlled by the following way.
(i) The use of fuel in dung cars should be economized to control acid rain.
(ii) By using pollution control equipments emission of So2 and No2 from industries and power plants should be reduced.
(iii) To correct the adverse effects and bad effects of acid rain liming of lakes and soils should be done.
14. Write explanatory note on deplication of ozone layer.
Ans: Ozone layer is a gaseous layer in the atmosphere. It exists about30 to 60 km above the surface of the earth. It is like an umbrella that protects the living beings and plants from the dangerous and harmful Ultra Violet Rays. The ozone layer is there at about 30 to 60 km above the earth’s surface. It is a part of the earth’s atmosphere. It acts like protective umbrella and protects plants and animals from the harmful ultra violet rays of the sun. It acts like a filter and allows the essential rays to pass through it. A British Antarctic Survey team in 1985 detected 40% loss in the ozone layer over the Antarctica.
After that scientists have found that a synthetic chemical called CFC( cloro. Fluoro Carbon) has damaged the ozone layer. It is used in hair sprays, deodorants, shaving creams and many other cosmetic materials. It is also used in refrigerators. These cosmetic products are used all over the world; chlorine present in CFC mainly damages the ozone layer. Many studies here pointed out that if the use of CFC remains at the present level, ozone layer will be damaged wherever chlorine gets concentrated. When the ozone layer is damaged ultra violate ray will come to earth’s surface in full intensity and severely damage plants and animals. Therefore the ozone layer should be protected with all seriousness.
15. Write on the various process of formation of wasteland.
Ans: Wasteland means the land that suffering from environmental degradation and failing productivity. The sandy area, snow covered area, guilled area, barren land water logged area jhum affected areas are considered as wasteland.
Wasteland are formed by natural process and man made activities. Wasteland are formed by deforestation, overgrazing erroneous agricultural practices, mining etc.
16. Write a note on the effects of application of pesticides in agriculture.
Ans: Following are the effects of application of pesticides in
(i) Animals and human excreta may contain pathogens that contaminate the soil and crops. These also affect the health of man and animals agriculture.
(ii) Through food chain the radioactive dust may find its way from the soil into crops, animals and human.
(iii) Plants can absorb many pesticides and their degraded products E and nay reach humans and animals through food chain which may prove a very harmful.
(iv) The chemicals and pesticides are used in the field of agriculture field. These chemicals and pesticides can alter the basic composition of the soil.
(v) The quality of soil is spoiled due to the use of inorganic fertilizers in the long run.
(vi) The useful soil organisms which contribute in fertility and structure of the soil may killed through the chemicals and pesticides.
17. Discuss the salient features of the Water prevention and Control of population Act, 1974.
Ans: The Water (prevention and Control of population) Act, 1974:
In Articles 249 and 250 of the constitution has provided the parliament has no power to make laws of the state with respect to any of the matter aforesaid expect.
In pursuance of clause.
(i) of Article 252 of the constitution resolutions have been passed by all Houses of the Legislatures of the Legislatures of the states of Assam, Bihar, Gujarat, Haryana, Himachal pradesh, Jammu and Kashmir, Karnataka, Kerala, Madhya pradesh, Rajasthan, Triputa and west Bengal to the effect that matters aforesaid should be regulate in those states by parliament by passing laws To provide for the prevention and control of water pollution and maintaining an Act is It is essential The Act is essential for restoring of wholesomeness of water, for the establishment and with a view to carrying out the purpose aforesaid of Boards for the prevention an control of water pollution. For conferring on and assigning to such Boards powers and function relating there to and for matters connected there with.
18. Write about the importance of water conservation and its methods.
Ans: Following are the importance of water conservation and its methods:
(a) In water conservation reducing irrigation losses such as use of lined or covered canals, using water in the early morning or at late evening. use of sprinkling and drip method etc. is very helpful.
(b) To conserve water in sandy regions horizontal barrier of asphalt is placed below the soil surface to escape from quick evaporation of water.
(c) To conserve water in irrigated area some chemical wetting agents are used to increase the water intake of the soil.
(d) Water is conserved by making some boundary of soil barrier which prevent the quick run of rain water in plains pertinently in paddy field.
(e) Water is allowed to flow to the farming area and in foothills the course of the rebuilds are changed.
(f) To conserve water digging large pond is necessary.
(g) To conserve water the small embankments is hilly-slopes allow rain water to wait more and thus water gets more time to infiltrate.
(h) To conserve water re-use and economic use of it also helpful.
(i) Person can reduce the misuse and overuse of water in the area, where water is already in shortage and where water shortage is ahead pricing in water supply.
(j) Soil is left farrow far one or two seasons which increase its water conserving capacity.
(k) To conserve water in dry area or in the area under the affect of desertification the creation of new watershed or revival of old watersheds also very helpful.
19. Write how are the forests beneficial to mankind?
Ans: Forest are beneficial to mankind in the following way:
(i) Forests supplies food crops to the man, animals and the different species.
(ii) Forest helps in air purification.
(iii) Forest controls the climates.
(iv) Some industries like match box industry, plywood industry etc are being set up on the basis of forest.
(v) Forest saves the soil erosion increase fertility of soil, increase the water absorbing capacity of soil etc.
(vi) Forest supplies fuel wds for household use and raw materials for industrial use.
(vii) It also supplies cane, bamboos etc. that are very essential for building houses.
(viii) Forest can increase the natural beauty which gives pleasure and helps in the development of tourism industry.
(ix) To preserving the scarce animals, birds, various types of trees. forest is very beneficial.
20. Write about the flood as a disaster; its causes and management.
Ans: Flood is considered as a disaster. There are various causes of flood.
These are as follows :
(i) Due to deforestation river flood may occur very heavily.
(ii) One of the main cause of flood s overgrazing.
(iii) Rapid industrialization is one of the main cause of flood.
(iv) Coastal areas are occasionally flooded by unusually high tides induced by severe winds over ocean surfaces.
(v) Floods occur due to heavy rain sometimes combined with meeting snow which causes the rivers which causes the rivers to overflow their blanks
(vi) Floods occur when vegetation and soil cannot absorb all the water.
(vii) Mining is also one of the important causes of flood.
(viii) Global warming is also considered as causes of flood. Following are the management of flood control:
(i) The construction of embankments on lower beaches of rivers to divert flood water is one of the major methods of flood control.
(ii) One of an important method of flood control is reforestation.
(iii) Construction of spars which control both flood and bank erosion is one of the most mentionable method of flood control.
(iv) To provide sufficient protection against flood dams help very friendly. River dams is also a method of control.
(v) By restoring vegetation and institution efficient methods of soil management and conservation flood can be control,
21. Write on the harmful effect of river dam.
Ans: There are various harmful effect of river dam. Some of them are as follows:
(a) Due to river dam tribal peoples who lives near the river are displaced which making them isolated from their native lands and relatives and and some social issues are emerging.
(b) Large dams causes the fall of land fertility through water logging.
(c) Large dams helps in breeding of vector and spread of vector borne diseases
(d) Large dams creates two-environmental problem like water logging and salinization of farming land.
(e) Large dams reduces water flow and silt deposition in river.
(f) Through the excess use of irrigation facilities large dams are also responsible for the environmental problems.
(g) Large dams enriches the risk of earthquake and unseasonal flood. (h) Due to river dam deforestation at large rate by submerging a vast area can be caused etc.
22. Write a note on Acid rain and its effect.
Ans: When rainwater contains acids, it is called acid rain. Due to the presence of pollutants like oxides of sulphur, nitrogen and carbon in the ir, rain water transform them into weak acids and finally comes down to the surface of the earth as acid rain. Amount of acidity depends on the amount of pollutant dissolved. The pollutants are spread over a large area as they are in gaseous state. They are carried by wind and cloud to s great distance. So, acid rains are not confined to the area where the gaseous emissions originate. Acid rains are often called the lake killers’ as these rains are one of the main causes of deaths of lakes. Acid rains kill all aquatic lives including plants and animals in lakes, ponds, rivers etc.
The productivity of soils is also affected as the acid rain destroys the mineral elements and other nutrients of the soil. Some forests of Canada, Germany and USA are largely damaged due to acid rains. In Canada 50,000 lakes have been affected by acid rains and out of these 50.000 lakes, 140 have been declared dead. Acid rain has its adverse effects on human beings also but the mode of human diseases or deaths’ caused by acid rains is not properly understood as yet. Taj Mahal, the world famous marble monument at Agra, has been affected by the emissions of sulphur dioxide and other gases from Mathura Oil Refinery and it has lost its original glow. As the studies undertaken by BARC (Bhabha Atomic Research Centre) and WMO (World Meteorological Organization) indicate, the effect of the acidity in rainwater is not so alarming in Indian cities.
Hi, I’m Dev Kirtonia, Founder & CEO of Dev Library. A website that provides all SCERT, NCERT 3 to 12, and BA, B.com, B.Sc, and Computer Science with Post Graduate Notes & Suggestions, Novel, eBooks, Biography, Quotes, Study Materials, and more.
