Water Resources 10 NCERT Topic Wise Question Bank
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TOPIC WISE QUESTION BANK
Nature and Sources of Water
What kind of resource is water? (2 marks)
How much of the world's water exists as oceans and freshwater? (2 marks)
How much of the world’s water exists as fresh water? (2 marks)
Which are the sources of freshwater? (2 marks)
Identify the sources of fresh water supply. (2 marks)
Which is the major source of freshwater in India? (2 marks)
State any two sources from which freshwater can be obtained under the hydrological cycle. (2 marks)
Water Scarcity and Conservation
What is the situation regarding water scarcity in post-independent India? (5 marks)
What are the causes of water scarcity in available areas? (3 marks)
Mention two causes of water scarcity. (2 marks)
State any one reason for conservation of water resources. (2 marks)
State two objectives of rainwater harvesting? (2 marks)
What are two measures of conservation of water resources? (2 marks)
Give four major uses of water. (2 marks)
Give 2 examples of over-exploitation of water resources. (2 marks)
Hydroelectric Power and Dams
How much hydroelectric power is produced in India? (2 marks)
What is a dam? (2 marks)
How are dams classified on the basis of structure and the material used? (3 marks)
Which project has been constructed in the Satluj-Beas River Basin? (2 marks)
Where is the Hirakud Project and what is its advantage? (3 marks)
On which river Salal Dam is built? (2 marks)
Multi-purpose Projects and Opposition
What is a multi-purpose project? State two purposes, which are fulfilled by multi-purpose projects. (3 marks)
Name any Multi-purpose project in India and give three contributions of that project. (5 marks)
Why have multi-purpose projects and large dams been opposed? State one reason. (2 marks)
Which river is called as ‘river of sorrow’? (2 marks)
In which state were the farmers agitated over the higher priority given to the water supply in urban areas? (2 marks)
Which state governments have raised objections over the diversion of more water and where? (2 marks)
Why have the dams triggered floods? (2 marks)
Which are the two social movements that have been started against multi-purpose projects? (2 marks)
Who gets benefits from multi-purpose projects? State any two sections of society. (2 marks)
What are the social consequences of building big dams? (5 marks)
What is an ecological consequence of irrigation under multi-purpose projects? (2 marks)
Historical and Traditional Water Harvesting
In whose kingdom in ancient India, dams and lakes were built? (2 marks)
What did Nehru say about dams and why? (2 marks)
What was the position of the rainwater harvesting system in ancient India? (2 marks)
Give any one example of the rainwater harvesting system in ancient India. (2 marks)
What method was developed in the flood plains of Bengal to irrigate their fields? (2 marks)
Which methods were used in arid and semi-arid regions for irrigation? (2 marks)
What were the different methods of traditional rain-water harvesting? (5 marks)
Give a short note on Rooftop rainwater harvesting. (3 marks)
What are tankas? (2 marks)
What was the length and breadth of a tank in Phalodi? (2 marks)
What is remarkable about Gendathur, a remote backward village in Mysore? (2 marks)
What makes Tamil Nadu stand out with regard to rainwater harvesting? (2 marks)
Which system of tapping stream water is prevalent in Meghalaya? (2 marks)
Groundwater and Freshwater
What do you understand about underground water? Mention two areas where underground water is abundant. (3 marks)
Give two reasons why precipitation is called the primary source of water on earth. (2 marks)
QUESTIONS OF 3/5 MARKS
Answers should be in about 80/100 words.
Question 1.
Give some facts and figures about water in the world.
Answer:
Some facts and figures about water are given below :
96.5 per cent of the total volume of world’s water exists as oceans.
2.5 per cent of the total volume of world’s water exists as freshwater. 70 per cent of the fresh water occurs as ice-sheets and glaciers in Antarctica, Greenland and the mountainous
regions of the world. Only less than 30 per cent is stored as groundwater in the world’s aquifers.The total renewable water resources of India are estimated at 1,897 sq. km per annum.
India receives nearly 4 per cent of the global precipitation and ranks 133 in the world r in terms of water availability per person per annum.
By 2025, it is predicted that large parts of India will join countries or regions having absolute water scarcity.
Question 2.
In Israel average annual rainfall is 25 cm but there is no shortage of water but in India, average rainfall is 114 cm but here we find drought in one region or the other every year. Why ?
Answer:
In Israel large scale projects to desalinate sea water, direct water from rivers and reservoirs in the north, make optimal use of groundwater and reclaim flood overflow and sewage have been undertaken. On the other hand, in India there is no proper arrangement of using rainwater. As a result of it, most of the water flows in to drains and to the sea. The rainy season is only for three months. Thereafter there is no rain for remaining nine months. As a result of these conditions we, in India, face shortage of water.
Question 3.
Explain three causes of water scarcity.
Or
Water scarcity in most cases is caused by over-exploitation, excessive use and unequal access to water among different social groups.” Explain the meaning of statement with the help of
examples. [CBSE 2016-17]
Answer:
The statement means that there are various reasons for the scarcity of water as mentioned below :
Over-exploitation
Excessive use
Unequal access of water among different social groups.
See Textbook Question 2(2).
Question 4.
Is it possible that an area or region may have ample water resources but is still facing water scarcity ? Explain with the help of three relevant examples.
Answer:
It is possible that an area or region may have ample water resources, but is still facing water scarcity.
Such scarcity may be due to bad quality of water. The available water may be polluted by domestic and industrial wastes, chemicals, pesticides and fertilisers used in agriculture, thus making it harmful for human use.
Growing population and consequent greater demands for water.
Own wells/tubewells and falling groundwater level affecting water availability.
See Textbook Question 2(2).
Question 5.
Why is it important to conserve and manage our water resources ? Give any three reasons.
Answer:
It is necessary to conserve and manage our water resources due to the following reasons :
To safeguard ourselves from health hazards : Polluted water is not good for health. It may cause various kinds of water borne diseases. Water polluted by domestic and industrial wastes, chemicals, pesticides and fertilisers makes it hazardous for human use.
To ensure food security : Sufficient water is required for growing crops to meet the food requirement in the country. Shortage of water may lead to condition of drought and failure of crops.
To prevent degradation of our natural ecosystems : Over exploitation and mismanage¬ment of water resources will impoverish this resource and cause ecological crisis that may have profound impact on our lives.
We cannot imagine a life without water. Thus it is very necessary to conserve and manage our water without which there can be no life on earth.
Question 6.
How was the water conserved in ancient India ? Give some examples in support of your answer.
Answer:
The water was conserved in ancient India by constructing sophisticated hydraulic structures like dams built of stone rubble, reservoirs or lakes, embankments and canals for irrigation.
Some of the hydraulic structures in ancient India were as follows :
In the first century B.C., Sringaverapura near Allahabad, had sophisticated water harvesting system channelling the flood water of the river Ganga.
During the reign of Chandragupta Maurya, dams, lakes and irrigation systems were extensively built.
Irrigation works have been found in many places viz., Kalinga (Orissa), Nagarjunakonda (Andhra Pradesh), Bennur (Karnataka) and Kolhapur (Maharashtra).
In the 11th century, Bhopal Lake was built. It was one of the largest artificial lakes of its time.
In the 14th century, the tank in Hauz Khas, Delhi was constructed by Iltutmish. It supplied water to Siri Fort area.
Question 7.
Name any two multipurpose projects of India. State four objectives of multipurpose projects.
Answer:
(1)
Bhakra-Nangal Project in the Satluj-Beas river basin.
Hirakud Project in the Mahanadi basin.
(2) Four objectives of multipurpose projects are as given below :
Electricity generation
Irrigation
Flood control
Inland navigation
Fish breeding.
See Textbook Question 2(3) also.
Question 8.
What is a dam ? How are they classified ?
Or
What is a dam ? Describe the classification of dams on the basis of their structure and materials used and height.
Answer:
(1) A dam is a barrier across flowing water that obstructs, directs or retards the flow, often creating a reservoir, lake or impoundment. It has a section called a spillway or weir over which or through which water flows intermittently or continuously.
(2)
Based on structure and the materials used, dams are classified as timber dams, embankment dams or masonry dams.
According to the height, dams can be categorised as large dams and major dams or alternatively as low dams, medium height dams and high dams.
Question 9.
Describe the factors that are responsible for the poor condition of India’s rivers – both smaller and big rivers.
Answer:
The following factors are responsible for the poor condition of India’s rivers :
(1) Smaller rivers :
The growing domestic, municipal, industrial and agricultural demand it water from rivers has affected the quality of water. The volume of rivers has been reduced as more and more water is being drained out of them.
A heavy load of untreated sewage and industrial effluents are emptied into the rivers. This also affects the self-cleansing capacity of the rivers leading to rising pollution of their water. As a result of above factors, the smaller rivers have all turned into toxic streams.
(2) Big rivers : These rivers have been affected by the following factors :
Population growth
Agricultural modernisation
Urbanisation
Industrialisation : Industries are heavy users of water and also require hydroelectric power to run them.
For example in Delhi, a large amount of domestic and industrial waste falls in the Yamuna river that leads to water pollution. Thus, even the big”rivers like the Ganga and Yamuna are far from being pure and efforts are being made to clean the rivers.
Question 10.
What is a multi-purpose river project ? Give four objectives of these projects ?
Answer:
(1) Dams are referred to as multi-purpose projects where the many uses of the impounded water are integrated with one another. Dams are now built not just for irrigation but for electricity generation, water supply for domestic and industrial uses, flood control and recreation.
(2) The objectives of the projects were as mentioned below :
It would integrate development of agriculture and the village economy with rapid industrialisation and growth of the urban economy. It was thought that they would lead the nation to development and progress, overcoming the handicap of its colonial past.
These projects generate hydro-electricity. For example the Bhakra-Nangal project water is being used for hydel power production.
The projects are useful for irrigation as is the case of Bhakra project.
Flood control : These projects help in the control of floods. For example the Hirakud project in the Mahanadi basin integrates conservation of water with flood control.
The other objectives are navigation, fish breeding, water supply for domestic and industrial uses and to encourage tourism.
Also see Textbook Question 2(Hi).
Question 11.
Describe the factors that are responsible for the various objections against the multi-purpose projects.
Answer:
The factors that are responsible for the various objections against the various multi-purpose projects are as given below :
Failure of the projects to achieve their objectives.
Some dams that were constructed to control floods were responsible for the floods due to sedimentation in the reservoir.
Generally, big dams are not successful in controlling flood at the time of heavy and excessive rainfall because in such cases the release of water from dams aggravated the flood situation. This has happened in Maharashtra and Gujarat in 2006. The floods have not only devastated life and property but also caused extensive soil erosion.
Sedimentation deprived flood plains of silt, a natural fertiliser and was responsible for land degradation.
Multi-purpose projects induce earthquakes, cause water-borne diseases and pests and pollution resulting from excessive use of water.
Question 12.
What is rainwater harvesting ? How was it used in ancient times ?
Or
How is rainwater harvesting carried out in semi-arid regions of Rajasthan ? Explain. [CBSE 2016-17]
Or
What is rainwater harvesting ? Explain any two different methods of rainwater harvesting in different regions of India.
Or
Why are different water harvesting systems considered a viable alternative both socio-economically and environmentally in a country like India ?
Answer:
(1) Rainwater harvesting is a technique of increasing the recharge of groundwater by capturing and storing rainwater by constructing structures, such as dugwells, percolation pits, checkdams.
(2) Keeping into view the disadvantages and rising resistance against the multi-purpose projects, water harvesting system is considered a viable alternative both socio-economically and environmentally.
(3) Ancient Times :
In ancient India, along with the sophisticated hydraulic structures, there existed an extraordinary tradition of water-harvesting system.
People had in-depth knowledge of rainfall regimes and soil types.
They had developed wide ranging techniques to harvest rainwater, groundwater, river water and flood water in keeping with the local ecological conditions and their water needs.
In hilly and mountainous regions, people built diversion channels like the ‘guls’ or ‘kuls’ of the western Himalayas for agriculture. Rooftop rainwater harvesting wras commonly practised to store drinking water.
In the flood plains of Bengal, people developed inundation channels to irrigate their fields.
In arid and semi-arid regions, agricultural fields were converted into rain fed storage structures that allowed the water to stand and moisten the soil like the ‘Khadins’ in Jaisalmer and ‘Johads’ in other parts of Rajasthan.
In Bikaner, Phalodi and Barmer, almost all the houses had underground tanks for storing drinking water.
Also see Textbook Question 3(1) and (2).
Question 13.
What is rooftop rainwater harvesting system ? In which state is it compulsory to follow this system ?
Answer:
(1) Rooftop rainwater harvesting means the rainwater that falls on the sloping roofs of houses is taken through pipe into an underground tanka (circular holes in the ground), built in the main house or in the courtyard.
(2) In the semi-arid and arid regions of Rajasthan, particularly Bikaner, this practice was followed.
(3)
Roof top rainwater harvesting is the most common practice in Shillong, Meghalaya.
Tamil Nadu is the first and the only state in India which has made rooftop rainwater harvesting structure compulsory to all the houses across the state. There are legal provisions to punish the defaulters.
Question 14.
What is Bamboo Drip Irrigation system ?
Answer:
In Meghalaya, a 200-year-old system of tapping stream and spring water by using bamboo pipes is prevalent. About 10-20 litres of water enters the bamboo pipe system, gets transported over hundreds of meters, and finally reduced to 20-80 drops per minute at the site of the plant. Bamboo pipes are used to divert perennial springs on the hilltops to the lower reaches by gravity.
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