Bihar Board Class 10 Science Solutions Chapter 16 Management of Natural Resources

 

Bihar Board Class 10 Science Chapter 16 Management of Natural Resources InText Questions and Answers

Intext Questions (Page 269)

Question 1.
What changes can you make in your habits to become more environment-friendly ?
Answer:
We can become more environment friendly in various ways. We can pursue the maxim of three R’s i.e., Reduce, Recycle and Reuse and contribute to this mission in a very effective way.

Question 2.
What would be the advantages of exploiting resources with short-term aims ?
Answer:
The advantage is to reap huge profit without any accountability.

Question 3.
How would these advantages differ from the advantages Of using a long-term perspective in managing our resources?
Answer:
Exploiting resources with short-term aim is just to reap huge profit while using with a long-term perspective is to reap the benefit in a sustainable manner so that these will last for the generations to come.

Question 4.
Why do you think there should be equitable distribution of resources ? What forces would be working against an equitable distribution of our resources ?
Answer:
Mother earth is for all. Every living being has an equal right to the vast resources of the earth. If any body is using excessively means some where else somebody is being deprived of it. And then the struggle begins which leads to imbalance in the environment. But there are handful of rich and powerful industrialists who see these resources just as a means to reap huge profits. They are the main threats to equitable distribution of our resources.

Intext Questions (Page 273)

Question 1.
Why should we conserve forests and wildlife ?
Answer:
Forests are ‘biodiversity hotspots’. One measure of the biodiversity of an area is the number of species found there. However, the range of different life forms (bacteria, fungi, fern s, flowering plants, nematodes, insects, birds, reptiles and so on) is also important. One of the main aims of conservation is to try and preserve the biodiversity we have inherited. Experiments and field studies suggest that a loss of diversity may lead to a loss of ecological stability.

Question 2.
Suggest some approaches towards the conservation of forests.
Answer:
Forest resources ought to be used in a manner that is both environmentally and developmentally sound. In other words, while the environment is preserved, the benefits of the controlled exploitation go to the local people, a process in which decentralised economic growth and ecological conservation go hand in hand.

Intext Questions (Page 276)

Question 1.
Find out about the traditional systems of water harvesting/management in your region.
Answer:
Water harvesting is an age-old concept in India. Khadins, tanks and nadis in Rajasthan, bandharas and tals in Maharashtra, bundhis in Madhya Pradesh and Uttar Pradesh, ahars and pynes in Bihar, kulhs in Himachal Pradesh, ponds in the Kandi belt of Jammu region, and eris (tanks) in Tamil Nadu, surangams in Kerala, and kattas in Karnataka are some of the ancient water harvesting, including water conveyance, structures still in use.

In Rajasthan, khadins are more prevalent. First designed by the Paliwal Brahmins of Jaisalmer, western Rajasthan in the 15th century, this system is still used in many parts of the state. A khadin, also called a dhora is designed to harvest surface runoff water for agriculture. Its main feature is a very long (100-300 m) eastern embankment built across the lower hill slopes lying below gravelly uplands.

Sluices and spillways allow excess water to drain off. The khadin system is based on the principle of harvesting rainwater on farmland and subsequent use of this water-saturated land for crop production.

Question 2.
Compare the above system with the probable systems in hilly/mountainous areas or plains or plateau regions.
Answer:
Water harvesting system in the hilly areas are quite different from those of plain areas. Like in Himachal Pradesh, parts of it had evolved a local system of canal irrigation called kulhs over four hundred years ago. The water flowing in the streams was diverted into man-made channels which took this water to numerous villages down the hillside. The management of the water flowing in these kulhs was done by a common agreement between all the villages.

Interestingly, during the planting season, water was first used by the village farthest away from the source of the kulh, then by villages progressively higher up. These kulhs were managed by two or three people who were paid by the villagers. In addition to irrigation, water from these kulhs also percolated into the soil and fed springs at various points.

Question 3.
Find out the source of water in your region/ locality. Is water from this source available to all people living in that area ?
Answer:
The sources of water in my locality are ground water and the municipality supply. Sometimes, especially in summer season, water from these sources becomes scant.

Bihar Board Class 10 Science Chapter 16 Management of Natural Resources Textbook Questions and Answers

Question 1.
What changes would you Suggest in your home in order to be environment-friendly ?
Answer:
By pursuing the maxim of there R’s i.e., Reduce, Recycle and Reuse, we can save the environment in an effective way.
Reduce means to use less, I would save electricity by switching off unnecessary lights and fans, prefer to walking or cycling than using a vehicle, turn off the engine at red lights, repair leaky taps, and would not wast food etc.

Recycle means collect used things like plastic, paper, glass and metal items and recycle these materials to make required things instead of synthesising or extracting fresh plastic, paper, glass or metal. And Reuse refers to use things again and again. For example, instead of throwing away used envelopes, they can be used by reversing.

Question 2.
Can you suggest some changes in your school which would make it environment-friendly ?
Answer:
As discussed in the previous answer, pursuing the maxim of three R’s is the best way to become environment-friendly.

Question 3.
We saw in this chapter that there are four main stakeholders when if comes to forests and wildlife. Which among these should have the authority to decide the management of forest produce ? Why do you think so ?
Answer:
Out of the four stakeholders viz., the local people, the Forest Department, the industrialists, and the wildlife and nature enthusiasts, I think the best authority to decide the management of forest produce will be the local people i.e., the people who live nearby or in the forests. Because, the local people use the forest in a sustainable manner. For centuries, the local people had been using the forests but they had developed such practices that an optimum amount of produce is left for all generations to come.

Besides, the traditional use of foreset areas by shepherds etc. only ensure the balance in the forests ecology. Further, management of forests by keeping the local people out only leads to damage of the forests. In fact, forest resources ought to be used in a manner that is both environmentally and developmentally sound, i.e., keeping the environment preserved, the benefits of the controlled exploitation go to the local people.

Question 4.
How can you as an individual contribute or make a difference to the management of (a) forests and wild-life, (b) water resources and (c) coal and petroleum ?
Answer:
(a) Forests and wildlife : Forests resources cannot be handled without an active participation of the local people. An example of it is of sal forests of Arabari which underwent a remarkable recovery. So, I will ensure people’s active participation. I will also ensure an equitable distribution of resources in a sustainable manner so that all and not just a handful of rich and powerful people, benefit from the development of these resources.

(b) Water resources : During our day-to-day life knowingly or unknowingly we waste water which must be stopped. I will ensure that I would cultivate habits so that water can be saved. Further, by pursuing any water harvesting technique, we can also conserve water.

(c) Coal and petroleum : These are the main source of energy today. We can save them in many ways.

For example :

• Using fluorescent tubes.
• Swithing off unnecessary electric and electronic devices.
• Using solar devices.
• Prefer walking or cycling than using vehicle.
• Even if we use vehicle, it should be turned off while waiting on red lights.
• Using stairs instead of lifts.
• Keeping the air pressure in the tyres right.

Question 5.
What can you as an individual do to reduce your consumption of the various natural resources ?
Answer:
The consumption of various natural resources can be reduced in the following ways :

• Saving electricity by switching off unnecessary lights and fans.
• Use of fluorescent tubes.
• Using the stairs instead of lift.
• Prefer walking or cycling than to use vehicle.
• Turning off the engine of the vehicle while waiting on red lights.
• Repairing leaky taps.
• By not wasting food etc.

Question 6.
List five things you have done over the last one week to
(a) conserve our natural resources.
(b) increase the pressure on our natural resources.
Answer:
(a)

• Saved electricity by switching off unnecessary lights.
• Used stairs instead of lift.
• Preferred to walk instead of using vehicle.
• Repaired leaky taps.
• Used empty bottles of jams for storing purpose.

(b)

• Wasted water during bathing.
• TV remained on while I fell asleep.
• Frequently used heating devices.
• Used bulbs instead of fluorescent tubes.
• Wasted food.

Question 7.
On the basis of the issues raised in this chapter, what changes would you incorporate in your life-style in a move towards a sustainable use of our resources ?
Answer:
I would incorporate the maxim of three R’s, i.e., reduce, recycle and reuse in my life-style in a move towards a sustainable use of our resources.

Bihar Board Class 10 Science Chapter 16 Management of Natural Resources Textbook Activities

Activity 16.1 (Page 266)

Question 1.
Find out about the international norms to regulate the emission of carbon dioxide.
Answer:
The international norms to regulate the emission of carbon dioxide has been governed in Kyoto Protocol. It is an agreement made under the United Nations Framework convention on climate change (UNFCGC). Under the protocol, indus-trialised countries will have to: reduce their collective emissions of carbon dioxide and five other green house gases by 5.2% compared to the year 1990 (however, compared to the emissions level that would be expected by 2010 without the Protocol, this target represents a 29% cut). The national target have been set for 8% reductions for the European Union, 7% for the US, 6% for Japan, 0% for Russia and permitted increase of 8% for Australia and 10% for Iceland.

Clearly, most provisions of the Kyoto Protocol apply to the developed countries. The treaty was negotiated in Kyoto, Japan in December 1997 and came into force on February 16, 2005. As of December 2006, a total of 169 countries and other governmental entities have ratified the agreement. However, some of notable exceptions are the US and Australia. Countries like India and China, which have ratified the protocol, are not required to reduce CO2emissions under the present agreement.

Question 2.
How can we contribute towards meeting those norms ?
Answer:
Pollution is emerging out as one of the biggest problems of mankind. It is need of the hour to tackle the problem before it becomes a threat to human survival. But, it is not possible without an active participation of all. We can check the emission of CO2 in many ways, such as to prefer walking or cycling than to use a vehicle, keeping the engine turned off at red lights, using fluorescent tubes, using stairs than lift, avoiding use of heating devices in winters etc. These measures will reduce energy consumption and ultimately reduce the CCO2 emission by the power houses. The people can also be made aware of this problem so that more and more peopled participation can be ensured.

Activity 16.2 (Page 266)

Question 1.
There are a number of organisations that Seek to spread awareness about our environment and promote activities and attitudes that lead to the conservation of our environment and natural resources. Find out about the organisation(s) active in your neighbourhood/village/ town/city.
Answer:
In Delhi, there are many organisations which have been working for the conservation of our environment and natural resources. Some of them are :

• Centre for Science and Environment (CSE)
• Wildlife Trust of India (WTI)
• Development Alternations
• Kalpavriksh
• Srishti
• The Energy and Resources Institute (TERI)
• Vatavaran
• India Habitat Centre (IHC)

Question 2.
Find out how you can contribute towards the same cause.
Answer:
Pursuing the maxim of three R’s i.e., Reduce, Recycle and Reuse is the best way to contribute towards this cause. By saving electricity, water, coal and petroleum; collecting plastic, paper, glass and metal items to recycle them and make required things instead of synthesising, or extracting fresh products and by reusing things again and again, we can contribute towards the cause in an effective way.

Activity 16.3 (Page 268)

Question 1.
Check the pH of the water supplied to your house using universal indicator or litihus paper.
Answer:
Testing by universal indicator:
Universal indicator is a pH indicator that has different colours to indicate the range of pH of the solution it is in. Some water sample is taken in a test tube and with the help of a dropper, few drops of universal indicator are added into it. The colour of the solution will tell about the pH of the water.

Colour and meanings :
★ Red – Very acidic
★ Orange/Yellow – Acidic
★ Green – Neutral
★ Blue – Basic/Alkaline
★ Purple – Very basic/alkaline
Testing by litmus paper : Some water sample is taken in a beaker and a litmus paper is put into it. If the paper changes its colour, the nature of the sample can be find out. However, if there is no colour change, the pH is 7 i,e., neutral.
Colour and meanings :
★ Red – Acidic
★ Blue – Basic/Alkaline

Question 2.
Check the pH of the water in the local water body (pond, river, lake, stream).
Answer:
[Note : Just like the above activity, pH can be checked out.]

Question 3.
Can you say whether the water is polluted or not on the basis of your observations ?
Answer:
On file basis of the pH, it can be determined whether the water is polluted or not. The pH of pure water is neutral. But, the pollution changes the pH.

Activity 16.4 (Page 2681

Question 1.
Have you ever visited a town or village after a few years of absence ? If so, have you noticed new roads and houses that have come up since you were there last ? Where do you think the materials for making these roads and buildings came from ?
Answer:
Yes. I think the woods have come from the forests. The plywoods are also finished products of woods that too come from forests. The bricks are made up of soil and the steel we use is made from iron ores. Similarly, the sources of coal for building roads are mines. Cement is made from various ores, rocks, etc. Granite comes from rocks.

Question 2.
Try and make a list of the materials and their probable sources. –
Answer:

Question 3.
Discuss the list you have prepared with your classmates. Cain you think of ways in which the use of these materials caii be reduced ?
Answer:
We can definitely reduce the use of these materials. The use of wood can be reduced by using concrete beam instead of wood logs or by using aluminium or fibre windows and doors, etc. These days bricks made up of ashes are also available which are light in weight and are of unique characteristics. These can be used instead of bricks made up of soil. Similarly, roads can be built up using cement and used plastic instead of coaltar.

Activity 16.5 (Page 270)

Question 1.
Make a list of forest produce that you use.
Answer:
Wood, fruits, herbal medicines, bamboo, fish etc.

Question 2.
What do you think a person living near a forest would use ?
Answer:
The person living near the forest would use woods, fruits, herbs, dry leaves (for fuel), bamboo, fodder etc- Besides they use it for fishing and hunting and their animals use it as a place of grazing.

Question 3.
And what do you think a person living in a forest would use ?
Answer:
The person living in the forest is almost entirely dependent on it. They use woods, fruits, herbs, dry leaves (for fuel), bamboo, fodder etc. Besides they use it for fishing and hunting and their animals use it as a place of grazing.

Question 4.
Discuss with your classmates how these needs differ or do not differ and the reasons for the same.
Answer:
People who live in a town or village are less dependent on the forest than to those who live nearby or in the forest. A person who lives in a city needs forest produce such as fruits, woods, herbal medicines etc. But those who live in or near forest depend on it for their food and shelter. In addition to the above produce, they need firewood, dry leaves etc. for fuel; woods, bamboo for making huts, baskets etc. For the implements of agriculture, fishing and hunting they use forests. Besides, their cattle also graze the forest areas or feed on the fodder which is collected from forests.

Activity 16.6 (Page 271)

Question 1.
Find out about any two forest-products that are the basis for an industry.
Answer:
(i) Wood – for plywood industry.
(ii) Tendu leaves – for bidi industry.

Question 2.
Discuss whether this industry is sustainable in the long run. Or do we need to control our consumption of these products ?
Answer:
The way our forest resources are depleting, these industries are certainly not going to last long. Industries are exploiting the resources badly because they consider the forest merely a source of raw material. Once their need fulfils, they switch over to another area. There is a need of using these resources in a sustainable manner but it appears that the industries just don’t believe in this theory. And if suitable measures are not taken, the human kind may face struggle for survival. There is an urgent need of checking this practice and using our resources in a controlled manner.

Activity 16.7 (Page 273)

Debate the damage caused to forests by the following
(a) Building rest houses for tourists in national pafks.
Answer:
The rest houses made in forests become hub of activities which damage the natural peace and ecology of the forests. Besides the tourists see the forests just as a place of spending holidays. They cause damage to forests in many ways like by littering etc. Also they dump plastic packets and other wastes in forests. This way they have the forest environment.

(b) Grazing domestic animals in national parks.
Answer:
Grazing domestic animals in national parks damage the natural food chain or the pyramid of the forests. The animals who live in forests are deprived of their food which ultimately disturbs the balance of entire ecology of the forests.

(c) Tourists throwing plastic bottles/ covers and other litter in national parks.
Answer:
Tourists by throwing plastic bottles and other litter create pollution which affects the ecology of the forests badly. The litters rot and spread germs and disease which are very harmful for the environment.

Activity 16.8 (Page 273)

Question 1.
Villages suffering from chronic water shortage surround a water theme park in Maharashtra. Debate whether this is the optimum use of the available water.
Answer:
This is a typical example of unequal distribution of resources. In the one hand, villages do not have water for their basic need while in the other people are profusely using it for fun. This is something which should be checked out as soon as possible.

Activity 16.9 (Page 273)

Question 1.
Study the rainfall patterns in India from an atlas.
Answer:
The rainy season begins in India with the arrival of monsoon at the southern tip of the Indian peninsula generally by the first week of June. Subsequently, it divides into two – the Arabian Sea branch and the Bay of Bengal branch. The Arabian Sea branch reaches Mumbai about 10 days later on, approximately 10th of June. The Bay of Bengal branch also advances rapidly and arrives in Assam in the first week of June.

The lofty mountains ca$ue the monsoon winds to deflect towards the west over the Ganga plains. By mid-June, the Arabian Sea branch of the monsoon arrives over Saurashtra-Kuchchh and central part of the country. The Arabian Sea and the Bay of Bengal branches of the monsoon merge over the northwestern part of the Ganga plains. Delhi generally receives the monsoon showers from the Bay of Bengal branch by the end of June. By the first week of July, western U.P., Punjab, Haryana and eastern Rajasthan experience the monsoon. By mid-July, the monsoon reaches Himachal Pradesh and rest of the country.

The withdrawl or retreat of the monsoon is a more gradual process. It begins in northwestern states of India by early September. By mid-October, it withdraws completely from the northern half of the peninsula. The withdrawl from the southern half of the peninsula is fairly rapid. By early December, the monsoon has withdrawn from the rest of the country.

The islands receive the very first monsoon showers from the first week of April to the first week of May while withdrawl takes place from the first week of December to first week of January. By this time, the rest of the country is already under the influence of the winter monsoon.

Question 2.
Identify the regions where water is abundant and the regions of water scarcity.
Answer:
Regions of heavy rainfall (i.e., more than 200 cm a year) are Meghalaya, western coastal plains of Maharashtra, Goa, Karnataka, Kerala, West Bengal, Sikkim, Arunachal Pradesh and Assam. Regions of scanty rainfall (i.e., 50-100 cm of rain a year) are areas of upper Ganga valley, eastern Rajasthan, parts of Punjab and Haryana and Jammu & Kashmir, Deccan Plateau and the Indus Plain. Desert or semi-desert regions (less than 50 cm of rain a year) are – the northern part of Kashmir, southern Punjab, parts of Haryana, western Rajasthan, Thar, the Kachchh Peninsula and the rain shadow regions of the western Ghats.

Activity 16.10 (Page 277)

Question 1.
Coal is used in thermal power stations and petroleum products like petrol and diesel are used in means of transport like motor vehicles, ships and aeroplanes. We cannot really imagine life without a number of electrical appliances and constant use of transportation. So can you think of ways in which our consumption of coal and petroleum products can be reduced ?
Answer:
Most of the thermal power stations are based on coal. So, by saving electricity we can save coal. There are various ways in which we can save electricity like switching off unnecessary lights and fans, using fluorescent tubes, using stairs instead of lift etc. Similarly to save petroleum products, we can prefer walking or cycling instead of using vehicles, switch off the vehicles at red lights, use cookers to cook food, keep the air pressure in the tyres right etc.

Activity 16.11 (Page 278)

Question 1.
You must have heard of the Euro I and Euro II norms for emission from vehicles. Find out how these norms work towards reducing air pollution.
Answer:
Euro norms refer to the permissible emission level from petrol and diesel vehicles, which have been implemented in Europe. These norms require manufacturers to reduce the existing polluting emission levels in an efficient manner by making certain technical changes in their vehicles. The emission levels of CO (carbon monoxide) of Euro I is 2.75 g/km and of Euro II is 2.20 g/km. The implementation of these norms have helped to reduce the pollution level.

Bihar Board Class 10 Science Chapter 16 Management of Natural Resources NCERT Exemplar Problems

Short Answer Type Questions

Question 1.
Prepare a list of five items that you use daily in the school. Identify from the list such items that can be recycled.
Answer:
Paper, rexin bag, pen (plastic), steel lunch box, steel spoon. Paper, steel lunch box and steel spoon can be recycled.

Question 2.
List two advantages associated with water harvesting at the community level.
Answer:
Ground water keeps the layers of soil above it moist and prevents loss of water by evaporation. The water can be stored during rainy season and can be used when required.

Question 3.
In a village in Karnataka, people started cultivating crops all around a lake which was always filled with water. They addled fertilisers to their field in order to enhance the yield. Soon they discovered that the water body was completely covered with green floating plants and fishes started dyingdn large numbers. Analyse the situation and give reasons for excessive growth of plants and death of fish in the lake.
Answer:
Since people used excessive fertilisers in the fields, they were carried down to the lake during rains. As many fertilisers contain phosphates and nitrates, the water body became enriched with these chemicals. These chemicals promote excessive growth of aquatic plants and the surface of water was completely covered with plants. Depletion of light in the water body and insufficient availability of dissolved oxygen and nutrients resulted in the death of fish. ,

Question 4.
What measures would you take to conserve electricity in your house?
Answer:
(a) Put off the fans and lights when they are not required.
(b) Maximum use of solar radiation.
(c) Use of solar water heating system during winters.
(d) Use of fluorescent tubes or CFL.

Question 5.
Although coal and petroleum are produced by degradatioin of bio-mass, yet we need to conserve them. Why?
Answer:
Both the energy sources coal and petroleum take millions of years for their formation. As these resources are being utilised at a much faster rate than their formation, they will be exhausted in the near future, hence they need to be conserved.

Question 6.
Suggest a few measures for controlling carbon dioxide levels in the atmosphere.
Answer:
(a) Reducing the consumption of petrol in the automobiles.
(b) Using of CNG or clean fuel.
(c) Instead of burning litter preparing manure out of it.
(d) Treating smoke to remove harmful gases before discharging into atmosphere.
(e) Planting more trees.

Question 7.
(a) Locate and name the water reservoirs in Figures 16.1 (a) and (6).
(b) Which has an advantage over the other and why?

Answer:
(a) The water reservoir is a pond in the figure (a) and underground water body in the figure (b).
(b) Figure (b) has more advantage than the figure (a), because the advantages of water stored in the ground are many.

For example :

• It does, not evaporate.
• It spreads out to recharge wells.
• Provides moisture for vegetation over a wide area.
• It is protected from contaminatipn by animal and human wastes.
• It prevents breeding of insects.

Long Answer Type Questions

Question 8.
In the context of conservation of natural resources, explain the terms reduce, recycle and reuse. From among the materials that we use in daily life, identify two materials for each category. –
Answer:
Reduce means to use a material/commodity in lesser quantity e.g., electricity and water. Recycle means a material that is used once is collected and sent back to a manufacturer so that! they can make some other useful material from it e.g., plastic cups and buckets, glass tumbler, paper, metal objects. Reuse means using a thing over and over again instead of throwing it away. It does not involve the process of recycling either in-small or large scale e.g., used envelopes, plastic carry bags, bottles of jam.

Question 9.
Prepare a list of five activities that you perform daily in which natural resources can be conserved or energy utilisation can be minimised.
Answer:
For the conservation of natural resources and minimum utilisation of energy, following steps can be taken :
(а) Unused water in the water bottle may be used for watering plant.
(b) All the taps should be turned off properly before you go to sleep.
(c) Use of hose pipe for watering plants should be avoided.
(d) Vehicles should be washed only when they are dirty
(e) Fan and light should be used only when required.
(f) Solar water heating devices should be used.
(g) CFL should be used in place of conventional bulbs/tubes.

Question 10.
Is water conservation necessary? Give reasons.
Answer:
The total amount of fresh water is more than enough to meet the needs of human beings. But due to it’s uneven distribution, wide seasonal as well as yearly fluctuation in , rainfalls and wastage, water shortage is a chronic problem in – most parts of. the world. So, conservation of water is necessary,

Question 11.
Suggest a few useful ways of utilising waste water.
Answer:
(a) Waste water can be used for recharging the ground water.
(b) It can be used for irrigation.
(c) Treated municipal water can be used for washing cars, watering the gardens etc.
(d) Certain pollutants in sewage water can become fertiliser for various crops.

Question 12.
What is the importance of forest as a resource?
Answer:
Forests are renewable resources which
(a) Provide habitat, food, protection to wildlife.
(b) help in balancing CO2 and O2 of atmosphere.
(c) improves water holding capacity of soil,
(d) regulates water cycle.
(e) for human being, they are the source for all essential commodities like, fuel wood, timber pulp and paper etc.
(f) pro vide useful products like fruits, resins, gums, essential qils, bidi wrapper etc.

Question 13.
Why are the Arabari forests of Bengal known ~ to be a good example of conserved forest?
Answer:
The forest department developed a strategy in which the village rs were involved in the protection of the forest. In return for the labour, the villagers were paid and also had some benefit in harvesting operations. They were allowed to collect wood and fodder on payment of nominal fee. In this way, by the active and willing participation of the local people, the sal forests of Arabari were conserved.