Complete NCERT Book Page wise Solution Class 10th as per Latest CBSE Syllabus
Chapter-3 Water Resources
The following page provides you NCERT book solutions for Class 10 social science, social science Class 10 notes in pdf are also available in the related links between the texts.
Very Short Answers:-
1.How much of the earth surface is covered with water?
Ans. About 3/4th.
1.Three-fourths of the earth’s surface is covered with water but there is still scarcity of water across the globe.’ Explain giving three reasons.
Ans. (1) 96.5 per cent of the total volume of world’s water is estimated to exist as oceans and only 2.5 per cent as freshwater. Nearly 70 per cent of this freshwater occurs as ice sheets and glaciers.
(2) The availability of water resources varies over space and time, due to variations in seasonal and annual precipitation.
(3) Water scarcity is also caused by over-exploitation, excessive use and unequal access to water among different social groups.
WATER SCARCITY AND THE NEED FOR WATER CONSERVATION AND MANAGEMENT
Very Short Answers:-
1.According to Fallen Mark, a Swedish expert, when does water stress occur?
Ans. According to Fallen Mark, water stress occurs when water availability is between 1,000 and 1,600 cubic meter per person per year.
1.’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 the statement with the help of examples.
Ans. (1) Over-exploitation: People carelessly use water when it is abundantly available. That is why, in the dry season shortage of water is faced by many places. Water is not judiciously used in the time of rain. Surface runoff becomes flood in the cities but not being stored for the future use.
(2) Excessive use: Industries and affordable class use maximum percentage of water available for usage. They don’t feel to save the excessive water supply, which eventually cause severe water scarcity.
(3) Unequal access: The people of wet areas are not sensible enough to store the excess for those in the dry areas. Moreover the rich and affordable classes do not bother to get water whatever situation may be due to their money power.
3.Define water scarcity. Explain any two causes of water scarcity in India.
Explain any three causes for water scarcity in most parts of India.
Describe the important factors responsible for the water scarcity in the world.
Analyze any five major reasons of water scarcity in India.
Explain any three causes of water scarcity.
Ans. (1) Water scarcity: Water scarcity is the lack of sufficient available water resources to meet the demand for water usage within a region.
Reasons behind water scarcity in India
The water scarcity is mostly man made due to excess population growth and mismanagement of water resources. Some of the major reasons for water scarcity are:
(a)Inefficient use of water for agriculture. India is among the top growers of agricultural produce in the world and therefore the consumption of water for irrigation is amongst the highest. Traditional techniques of irrigation causes maximum water loss due to evaporation, drainage, percolation, water conveyance, and excess use of groundwater. As more areas come under traditional irrigation techniques, the stress for water available for other purposes will continue. The solution lies in extensive use of micro-irrigation techniques such as drip and sprinkler irrigation.
(b)Reduction in traditional water recharging areas. Rapid construction is ignoring traditional water bodies that have also acted as ground water recharging mechanism. We need to urgently revive traditional aquifers while implementing new ones.
(c)Sewage and wastewater drainage into traditional water bodies. Government intervention at the source is urgently required if this problem is to be tackled.
(d)Release of chemicals and effluents into rivers, streams and ponds. Strict monitoring and implementation of laws by the government, NGOs and social activists is required.
4.How is agriculture aggravating the problem of water scarcity in India? Explain.
Ans. (1) Water scarcity is an outcome of large and growing population and consequent greater demands for water and unequal access to it.
(2) A large population means more water not only for domestic use but also to produce more food.
(3) To facilitate higher food grain production, water resources are being over-exploited to expand irrigated areas and dry-season agriculture.
(4) Most farmers have their own wells and tube wells in their farms for irrigation to increase their produce.
(5) It may lead to falling groundwater levels, adversely affecting water availability and food security of the people.
5.How does increasing number of industries exert pressure on existing fresh water resources?
Ans. (1) Industries use water and also require power to run them. Much of this energy comes from hydro-electric power.
(2) Today in India hydraulic power contributes approximately 22% of total electricity produced, depleting the ground level.
(3) Industrial waste pollutes rivers and lakes at a rapid pace.
(4) Industries are heavy users of water for various processes to be conducted by machines.
(5) Water is used as a major coolant for machines.
6.Why are dams considered to be a good source of conserving and managing water resources?
Ans. All the following mentioned requirements can be met with by constructing
(1) Industries are heavy users of water:
(2) They also require power which comes from hydro-electricity.
(3) Urbanization and its lifestyle have added pressure on water resources.
(4) Urbanization leads to dense population which results in over-exploitation of groundwater.
(5) They also provide water for irrigation.
1.How does urbanization and urban lifestyle lead to over-exploitation of water resources? Explain.
Ans. (1) Multiplying urban centers with large and dense populations has increased the demand for water.
(2) Urban lifestyles have not only added to water and energy requirements but have further aggravated the problem.
(3) The housing societies or colonies in the cities have their own groundwater pumping devices to meet their water needs.
(4) Fragile water resources are being over-exploited and have caused their depletion in several cities.
(5) Urbanization creates vast opportunities which attract people. This increasing population demands more water to fulfill their domestic needs.
2.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.
Ans. (1) There is a situation when water is sufficiently available to meet the needs of the people but the area still suffers from water scarcity. This scarcity may be due to bad quality of water.
(2) Water gets polluted by domestic and industrial wastes, chemicals, pesticides and fertilizers used in agriculture, thus, making it hazardous for human use.
(3) India’s rivers have turned into toxic streams.
(4) The assault on India’s rivers—from population growth, agricultural modernization, urbanization and industrialization is enormous and growing day-by -day.
3. What is the importance of water as a natural resource? Describe any two methods of conserving water.
Ans. (1) About three-fourth of the earth’s surface is covered with water. Only a small proportion (2.5 per cent) of it accounts for fresh water that can be put to use. This fresh Water is continually being renewed and recharged through the hydrological cycle. All water moves within the hydrological cycle ensuring that water is a renewable resource.
(2) Two methods of conserving water:
(i) Rooftop rain water harvesting is practiced to store drinking water particularly in Rajasthan.
(ii) In the floodplains of Bengal, people developed inundation channels to irrigate their fields.
(iii) In arid and semi-arid regions, agricultural fields were converted into rained storage structures that allowed the water to stand and moisten the soil like the ‘Chains’ in Jaisalmet and `Jihads’ in other parts of Rajasthan.
4.’Water is a very important and critical resource in India.’ Support the statement by explaining any three points.
Ans. (1) A huge population resides in India which demands more water not only for domestic use but also to produce more food. For higher food grain production farmers install their own tube wells which lead to falling groundwater level adversely affecting water availability.
(2) Multiplying urban centers with large and dense population have added to water and energy requirements. The housing societies have their own groundwater pumping devices to meet their water needs. But in this way, water resources are being over-exploited.
(3) To run the industries, availability of water is an essential factor. But, the waste material coming out from industries pollute the rivers.
5.How have industrialization and urbanization aggravated water scarcity in India?
Explain any three ill-effects of industrialization and urbanization on water resources in India.
How have industrialization and urbanization posed a great pressure on existing fresh water resources in India? Explain with examples.
Ans. (1) Industrialization: Industries are heavy users of water. They also require energy to run machines. Much of this energy comes from hydro-electric power.
(2) Urbanization: (I) Multiplying urban centers with large and dense populations and urban lifestyles have not only added to water and energy requirements but also have further aggravated the problem.
(ii) Most housing societies have their own groundwater pumping devices to meet their water needs. This leads to depletion of underground water.
6. Why is there an urgent need to conserve and manage our water resources? Mention three Reasons.
Why is the conservation and management of our water resources a dire necessity? Give five reasons.
`It is essential to conserve and manage our water resources.’ Support the statement with suitable examples.
Ans. Following are the reasons that we need to conserve and manage our water resources:
(1) Large growing population: This causes greater demand of water and unequal access of people to water resources. Greater demand means demand for food and rise in food grain production which needs more water.
(2) Over-exploitation of water resources: To expand irrigated areas and dry season, farmers have their own wells and tube wells which may lead to falling groundwater levels.
(3) Intensive industrialization: In industry for various purposes, water is heavily used. To run industries, power is required and 22% of it comes from hydro-electricity.
(4) Urbanization: Large and dense population adds to water demand and scarcity. Most pump groundwater to meet their needs and water tables are falling consistently.
(5) Lack of rainwater harvesting: It is not mandatory except in Tamil Nadu.
MULTI-PURPOSE RIVER PROJECTS AND INTEGRATED WATER RESOURCES MANAGEMENT
Very Short Answers:-
1.On which river is Chakra Nan gal Dam built?
Ans. Chakra Nan gal Dam is built on the river Sutlej.
2.Sadder Samovar Dam is built on which river?
Ans. Sadder Samovar Dam is built on the river of Narmada.
3.On which river is Konya Dam constructed?
Ans. Konya Dam is constructed on river Krishna.
4. Who proclaimed the dams as ‘the temple of modern India’?
Ans. Jawaharlal Nehru
5.In which state is the Teri Dam located?
6.On which river is the Teri Dam being constructed?
1.Explain any two consequences of changing crop pattern due to irrigation.
Ans. (1) The population of India is growing rapidly and demands its food security the government introduced schemes to the farmers to grow food crops twice or thrice a year. Earlier, the farmers depended on rainfall in the monsoon season for their yearly productive With failure in rain, they used to suffer a lot. Now-a-days farmers can take loan and use pumps to irrigate their land. Over and over irrigation to get good returns and using of fertilizers to retain the soil fertility, they, in turn, make the land exhausted and thus, the ultimately production is suffering.
(2) On the other hand on the event of drawing more and more water from the underground sources, the water table is also getting dried up. The fertilizer mixed water contaminates the canals and other water bodies. ,
2.Describe in details the aim of Narmada Bache Angolan.
Ans. (1) Narmada Bache Angolan is a Non-Governmental Organization (NGO) that mobilized tribal people, farmers, environmentalists and human rights activists against the Sadder Samovar Dam being built across the Narmada River in Gujarat.
(2) It originally focused on the environmental issues related to trees that would be submerged under the water.
(3) Recently, it has re-focused its aim to enable poor citizen, especially the ousters (displaced people) to get full rehabilitation facilities from the government.
3.How has irrigation changed the cropping pattern in many regions of India? Explain with the examples.
Ans. (1) Farmers shift to water intensive and commercial crops.
(2) This leads to Stalinization of the soil.
(3) This has transformed the social landscape and increasing gap between richer land owners and landless poor.
4.Explain three ways in which irrigation have changed the social landscape of the region.
Ans. (1) It has increased the social gap between the rich landowners and the landless poor.
(2) Dams have created conflicts between people who have different opinions on the use of water.
(3) Dams have created inter-state water disputes. For example, Krishna-Godavari water dispute.
5.Evaluate the role of dams in flood control with the help of suitable examples.
Ans. (1) Initially, it was expected that large dams would control flood as well as help conserve water.
(2) Ironically, the dams built to control floods have triggered floods due to sedimentation in the reservoirs.
(3) Big darns have been mostly unsuccessful in controlling floods at the time of excessive rainfall.
(4) The release of water from dams during heavy rains aggravated the flood situation in Maharashtra and Gujarat in 2006.
6.What is the reason behind Krishna-Godavari water dispute? Name the multi-purpose river valley project constructed on river Krishna.
Ans. Reasons behind Krishna-Godavari water dispute:
1.(i) Objection was raised by Karnataka and Andhra Pradesh governments regarding the diversion of more water of Korana by the Maharashtra government for a multi-purpose project.
(ii) The diversion would reduce downstream flow in the states of Karnataka and Andhra Pradesh which would adversely affect industry and agriculture.
(2) The multi-purpose river valley project constructed on river Krishna is Nagarjuna Sager Dam.
1.Mention any five advantages and five disadvantages of multi-purpose river projects.
Mention any three advantages and three disadvantages of multipurpose river projects. Or
Mention any six advantages of multi-purpose river projects.
Ans. (1) Advantages: Multi-purpose projects launched after independence with their integrated water resources management approach, were thought of as the vehicle that would lead the nation to the path of development and progress, overcoming the handicap of its colonial past.
(ii) Jawaharlal Nehru proclaimed the dams as the temples of modern India: the reason being that it would integrate development of agriculture and the village economy with rapid industrialization and growth of the urban economy.
(iii) Dams were built to impound rivers and rainwater that could be used later to irrigate agricultural fields.
(iv) Hydro-electricity is also generated which is provided to industries to run machines.
(v) Dams control floods at the time of excessive rainfall.
(vi) It protects the devastation of life and property and soil does not get eroded.
1) Multipurpose project affects the natural flow of water.
2) it cause the excessive sediments at the bottom of the river which makes stream beds rockier.
3) it causes the poor habitat of aquatic life.multi purpose projects causes no migration of aquatic fauna.
4) the dam submerged the vegetation and soil at the both of the bank of the river and causes flood plains.
5 ) multipurpose projects also causes new social movement like Narmada bachao andolan.
2.Mention the new social movements that have been a result of opposition to multi two movements that have been started to oppose multipurpose river projects in India. Why did they oppose to these projects?
(i) Narmada Bache Angolan was started against the Sadder Samovar Dam being built across the Narmada River in Gujarat.
(ii) Teri Dam Angolan—Resistance to these projects has primarily been due to the large’ scale displacement of local communities.
(2) The landowners and large farmers, industrialists and a few urban centers are benefitted from such projects.
(3) They oppose to these projects because.
(i) Construction of large dams leads to the large-scale displacement of the local communities.
(ii) The displaced people do not get full rehabilitation facilities from government.
(iii) Local people have to give up their land and livelihood.
2.Mention any three hydraulic structures of ancient India.
Highlight any three hydraulic structures as a part of water management programmed initiated in ancient India.
Ans. Three hydraulic structures of ancient India are as under:
(1) In the first century B.C. Sringaverapura near Allahabad had sophisticated water harvesting system channeling the flood water of the river Gang.
(2) During the time of Chandragupta Maura, dams, lakes and irrigation systems were extensively built.
(3) Sophisticated irrigation works have also been found in Kalong (Odessa), Nagarjunakonda (Andhra Pradesh), Banner (Karnataka), Kolhapur (Maharashtra), etc.
(4) In the 11th century, Bhopal lake, one of the largest artificial lake of its time was built.
(5) In the 14th century, the tank in Haul Khans, Delhi was constructed by Iltutmish for supplying water to Sire Fort area.
3.What is a multi-purpose river valley project? Mention any four objectives of it.
Describe the major objectives of multi-purpose river valley projects.
Ans. (1) Multi-purpose river valley projects generally refer to large dams that serve several purposes in addition to impounding the water of a river.
(2) Major objectives of multi-purpose river valley projects are as follows:
(i)These projects aim at providing irrigation water and power inputs which then enhances the food productivity.
(ii) Such projects involve construction of several large, medium and small dams on rivers with purpose of generation of electricity.
(iii)They are used to regulate river flow and ensure adequate supply of water during dry Periods.
(iv) Water supply for industrial and domestic purposes.
(v) These projects transmit benefits to distant places.
4.Explain the ecological problems being faced due to the multi-purpose river projects.
Ans. (1) Dams fragment rivers making it difficult for aquatic fauna to migrate especially for spawning.
(2) The reservoirs that are created on the floodplains also submerge the existing vegetation and soil leading to its decomposition over a period of time.
(3) Multi-purpose projects that were constructed to control floods have triggered floods which cause extensive soil erosion.
(4) Sedimentation also meant that the floodplains were deprived of silt, a natural fertilizer, thriller adding on to the problem of land degradation.
(5) Multi-purpose projects induced earthquakes, caused water borne diseases and pests and Pollution resulting from excessive use of water.
5.Define ‘a dam’. Describe any two problems caused due to multi-purpose projects.
Ans. (1) A dam is a barrier across flowing water that obstructs, directs or retards flow, often creating a reservoir, lake or impoundment. Dams refer to the reservoir rather than the structure.
(2) Two problems caused due to multipurpose projects are as follows:
(i) Regulating and damming of rivers affect their natural flow causing poor flow and excessive sedimentation at the bottom of the reservoir, resulting in rockier stream beds and poorer habitats for the rivers’ aquatic life.
(ii) The reservoirs that are created on the floodplains also submerge the existing vseegdetairin: and soil leading to its decomposition over a period of time.
6.’In recent years multi-purpose projects and large dams have come under great scrutiny and
`Multi-purpose projects and large dams have come under great scrutiny and opposition for a variety of reasons.’ Explain any five reasons.
`Why are large dams under scrutiny these days?’ Mention any three ill-effects caused by this on the environment. Explain any three reasons due to which large dams have come under great opposition I recent years.
Why have multi-purpose river projects come under great scrutiny and opposition? Explain any three reasons.
Ans. (1) Agree: (i) Regulating and damming of rivers affect their natural flow causing poor sediment flow and excessive sedimentation at the bottom of the reservoir.
(ii) It results in rockier stream beds and poorer habitats for the rivers’ aquatic life.
(iii) Dams also fragment rivers making it difficult for aquatic fauna to migrate.
(iv) The reservoirs created on the flood plains submerge the existing vegetation and soil leading to its decomposition.
(2) Disagree: (i) Dams are built for irrigation as well as for generating electricity.
(ii) Darns supply water for domestic and industrial use.
(iii) Initially, it was expected that large dams would control flood as well as conserve water.
7.Why are dams called multi-purpose projects? Explain any three reasons.
Why are dams referred to as multi-purpose projects? Explain any three reasons.
Ans. Dams are called multi-purpose projects because:
(1) Earlier they were built to impound rivers and rainwater could be used later for irrigation.
(2) Now, dams are built not only for irrigation but for generation of electricity, water supply for domestic use, flood control, recreation, inland navigation and fish-breeding.
(3) Thus, they are called multi-purpose projects.
(4) For example, in the Sutlej-Beas river basin, the Bhakra-Nangal project water is being used both for hydelpower production and irrigation.
8.’Why did Jawaharlal Nehru proudly proclaim the dams as the temples of modern India?’ Mention any four advantages of the dams.
What did Jawaharlal Nehru say about the dams and why? Explain.
Who proclaimed the dams as the ‘temples of modern India’? Explain any two reasons for it.
Dams are referred as the ‘temples of modern India’? Who said this and why?
Ans. (1) Dams have been proclaimed as ‘temples of modern India’ because they integrate development of agriculture and the village economy with rapid industrialization and grow of urban economy.
(2) Advantages of dam: (i) Irrigation, (ii) Electricity generation,
(iii) Water supply for domestic and industrial uses, (iv) Flood control,
(v) Recreation, (vi) Inland navigation,
9.Why is groundwater a highly overused resource?
Ans. Groundwater is a highly overused resource because:
(1) Water is essential for life and is needed in every sphere of life.
(2) To raise crops and earn money, farmers depend on groundwater resources.
(3) With the increase in development activities, new industries are being set up. Industries are the biggest consumers of water resources.
(4) Due to increasing urbanization process, new colonies and buildings are developed. They consume huge amount of water.
(5) Also, farmers and people in general, use their own wells and tube wells for irrigation and domestic purposes.
Very Short Answers:-
1.What is the reference used for ‘rainwater’ in Rajasthan?
Ans. Palarpani is the reference used for rainwater in Rajasthan.
2.Chains’ and `Jihads’ are the rain fed storages structures of which state of India?
Ans. Chains’ and `Jihads’ are the rain fed storages structures of Rajasthan in India.
3.Which state has made rooftop rainwater harvesting structure compulsory to all the houses across the state?
Ans. Tamil Nadu has made rooftop rainwater harvesting structure compulsory to all the houses across the state.
1.Why is the rooftop rainwater harvesting the most common practice in Shilling in spite of the fact that Cherapunjee and Mawsynram are situated only at a distance of 55 kames from there? Explain.
Ans. (1) Shilling receives heavy rainfall during monsoon period but the state faces acute water shortage during lean seasons.
(2) It is mainly due to lack of water storage system.
(3) Considering the limitations of surface and ground water in the state, the most reliable source of water in the dry months is harvested rainwater. The state, therefore, laid emphasis on rainwater harvesting.
2.Describe the rooftop rainwater harvesting technique.
Ans. Rooftop rainwater harvesting:-
(1) Rooftop rainwater is collected using PVC pipe.
(2) Water is filtered using sand and bricks.
(3) Underground pipe takes water to sump for immediate usage.
(4) Excess water from the sump is taken to the well.
(5) Water from the well recharges the underground. The water collected in the well can be used later for domestic purposes.
3.Explain any five techniques of rainwater harvesting used in India.
`Different regions had developed different techniques to conserve water.’ Illustrate.
Ans. Five techniques of rainwater harvesting in India are as under:
(1) In hill and mountainous regions, people built diversion channels like `gulls’ or lulls’ for agriculture.
(2) Rooftop rainwater harvesting is practiced to store drinking water in Rajasthan.
(3) In flood plains of Bengal, people developed inundation channels to irrigate their fields.
(4) 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 shadings’ and `Jihads’ in Rajasthan.
(5) Rooftop rainwater is collected using PVC pipes into the wells. The water thus collected can be used for various purposes.
4.Write the features of the tanks’ built in the houses of Bikaner, Paladin and Barmen
Ans. (1) The tanks could be as large as a big room; one household in Paladin had a tank that was 6.1 meters deep, 4.27 meters long and 2.44 meters wide.
(2) The tanks’ were part of the well-developed rooftop rainwater harvesting system and were built inside the main house or the courtyard.
(3) They were connected to the sloping roofs of the houses through a pipe.
(4) Rain falling on the rooftops would travel down the pipe and was stored in these underground `tanks’.
(5) The first spell of rain was usually not collected as this would clean the roofs and the pipes. The rainwater from the subsequent showers was then collected.
5.Why is rooftop rainwater harvesting important in Rajasthan? Explain.
Ans. (1) The rainwater stored in tanks’ is an extremely reliable source of drinking water when all other sources are dried up.
(2) Rainwater is considered the purest form of natural water.
(3) Many houses constructed underground rooms adjoining the tanks to beat the summer heat as it would keep the room cool.
(4) There is lack of perennial rivers in Rajasthan.
(5) The rainfall is not reliable in this region.
6.Explain the term, tanks’. Where were tanks built in India?
Ans. (1) The tanks’ were part of the well-developed rooftop rainwater harvesting system and were built inside the main house or the courtyard. They are built for storing drinking water. A tank could be 6.1 meters deep, 4.27 meters long and 2.44 meters wide.
(2) The tanks were built in the semi-arid and arid regions of Rajasthan, particularly in Bikaner, Paladin and Barmen
7.What is bamboo drip irrigation? Mention any two features of it.
Describe Bamboo drip irrigation system. In which state of India it is practiced?
Ans:-Features of bamboo drip irrigation:
(i) Bamboo drip irrigation system is 200 year old system of tapping stream and spring water by using bamboo pipe.
(ii) Bamboo pipes are used to divert perennial springs on the hilltops to the lower reaches by gravity.
(iii) The channel sections, made of bamboo, divert water to the plant site where it distributed into branches.
8.What is ‘rainwater harvesting system’? Which state in India has made compulsory?
Ans. (1) Rainwater harvesting is a technique of increasing the recharge of ground-water by capturing and storing rainwater by constructing structures such as dug wells, percolation pits and check dams.
(2) (i) Tamil Nadu has made this system compulsory to all the houses across the state.
(ii) There are legal provisions to punish the defaulters.
9.What role do `Gulls’ or ‘Kula’ of the Western Himalayas and `Chain’ and `Jihads’ in parts of Rajasthan play? Describe.
Ans. (1) In Western Himalayas people build diversion channels like `guls”or’
(2) In arid and semi-arid regions, agricultural fields were converted into rain-fed storage structures.
(3) These allowed the water to stand and moisten the soil like the shadings’ in Jaywalker and `Jihads’ in other parts of Rajasthan.
10.Why is the practice of rooftop rainwater harvesting slowly declining in Rajasthan? Which state has made rooftop rain water harvesting compulsory?
Ans. (1) (i) In western Rajasthan the practice of rooftop rainwater harvesting is on the decline.
(ii) This is because; plenty of water is available now due to the perennial Rajasthan Canal.
(iii) Some houses still maintain tanks as they do not like the taste of tap water.
(2) Tamil Nadu has made this system compulsory. There are legal provisions to punish the defaulters.
11.What are tanks? How are they useful for storing water?
What are tanks? Mention their uses.
Ans. (1) (i) In the semi-arid and arid regions of Rajasthan, almost all the houses traditionally had underground tanks for storing drinking water.
(ii) The underground tanks can have dimensions 6.1 m deep, 4.27 m long, 2.44 m wide.
(2) Uses : (i) We can use water in dry season.
(ii) It is useful to recharge the underground water.
(iii) It keeps the room cool.
12.Describe any three traditional methods of rainwater harvesting adopted in different parts of India.
Explain any three techniques of rainwater harvesting used in ancient India.
Examine five traditional methods of rainwater harvesting practiced in different parts of
Describe any three traditional methods of rainwater harvesting practiced in different parts of India.
Ans. (1) Rainwater harvesting is a technique by which recharge of water can be increased. It is done by artificial recharging of abandoned wells.
(2) Different methods of rainwater harvesting are as follows : (i) In hill and mountainous regions, people built diversion channels like the ‘gills’ or lulls’ in the Western Himalayas for agriculture.
(ii) Rooftop rainwater harvesting is commonly practiced to store drinking water in Rajasthan.
(iii) In the floodplains of Bengal, people develop inundation channels to irrigate their fields.
(iv) In arid and semi-arid regions, agricultural fields were converted into rained storage structures that allow the water to stand and moisten the soil like the shadings’ in Jaywalker and `Jihads’ in other parts of Rajasthan.
17.Describe the way, in which rainwater harvesting is carried out in the semi-arid and arid regions of Rajasthan? Highlight the importance of rainwater harvesting in these regions. Mention any two advantages of it.
Discuss how rainwater harvesting in semi-arid regions of Rajasthan is carried out.
How is rainwater harvesting carried out in semi-arid regions of Rajasthan? Explain.
Ans. (1) In semi-arid and arid regions of Rajasthan, particularly in Bikaner, Paladin and Barer, almost all the houses traditionally had underground tank or tanks for storing drinking water.
(2) The tanks could be as large as a big room; one household in Paladin had a tank that was 6.1 meters deep, 4.27 meters long and 2.44 meters wide.
(3) The tanks were part of the well-developed rooftop rainwater harvesting system and were built inside the main house or the courtyard.
(4) They are connected to the sloping roofs through a pipe and store rainwater in these underground `tanks’.
18.Why are different water harvesting systems considered a viable alternative both socio-economically and environmentally in a country like India?
`Rainwater harvesting system is viable alternative both by socio-economically and environmentally’. Support the statement with three examples.
Ans. (1) 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.
(2) In ancient India also, along with the sophisticated hydraulic structures, there existed an extraordinary tradition of various water-harvesting systems.
(3) People adopted different techniques in different areas. In hilly regions, people built diversion channels like the ‘guts’ or ‘kills’ for agriculture.
(4) Rooftop rainwater harvesting is commonly practiced to store drinking water, wheal in Rajasthan particularly
(5) In the floodplains of Bengal, people developed inundation channels to irrigate their fields. Khakis, Jihads and Tanks are the forms of rainwater harvesting practiced i Rajasthan.
VALUE BASED QUESTIONS
1.’There is shortage of water as compared to its demand.’ In the light of the above statement, what do you think are the reasons of water scarcity how can it be controlled?
Ans. (1) Reasons of water scarcity: (i) Urbanization. (ii) Industrialization. (iii) Over-exploitation of water resources. (iv) Growing population.
(2) Ways to control water scarcity: (i) judicious use of water. (ii) Rain water harvesting. (iii) Digging new ponds and tanks. (iv) Cleaning of existing ponds and tanks. (v) Keeping the flow of river undisturbed. (vi) Keeping water resources clean and pollution-free.
2.’Dams were proclaimed to be the temples of modern India. At the same time they have many disadvantages.’ In the light of the above statements, mention advantages and disadvantages of dams.
Describe any five disadvantages of constructing dams.
Ans. (1) Advantages of dams: (i) Irrigation.
(ii) Electricity generation.
(iii) Flood control.
(v) Water supply for domestic and industrial uses.
(vi) Inland navigation and fish breeding.
3.Government is announcing regularly to reduce water wastage. Explain any three human values required for compliance.
‘In spite of having ample water resources, some areas and several metropolitan- cities are facing water scarcity in India.’ Explain any three values which can help to overcome this problem.
Ans. (1) Public awareness: People should be made aware about water scarcity. At the time of sufficient availability of water, people do not use it wisely. Either it is wasted or misused by the people. Media can play an important role in bringing awareness among the people by making documentary film, advertisements, etc.
(2) Conservation of water: The tendency of conserving water need to be developed among the masses. People’s participation or initiatives are essential to conserve water. They should understand that every drop of water needs to be conserved.
(3) Importance of water: People should be made aware of the drastic effects of water scarcity. People need to be taught to stop the others whom they found wasting or polluting the water. It is essential that people should be sensitive enough towards the importance of water.