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NCERT Class 12 Geography Chapter 16 Water Resources
Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. CBSE Class 12 Geography Solutions are part of All Subject Solutions. Here we have given NCERT Class 12 Geography: Fundamentals of Human Geography, Geography: India People and Economy, Geography: Practical Work in Geography. NCERT Class 12 Geography Chapter 16 Water Resources Notes, NCERT Class 12 Geography Textbook Solutions for All Chapters, You can practice these here.
Water Resources
Chapter: 16
PART – II INDIA: PEOPLE AND ECONOMY
Very Short Type Questions Answer
1. Name the means of irrigation.
Ans: The various sources of water for irrigation are wells, ponds, lakes, canals, tube-wells and even dams.
2. Define hectare metre.
Ans: Hectare (symbol ha) is the metric unit of area that equals a square with 100 m side (1 hm2) or 10,000 square metres. The term hectare is introduced in French, from the Latin area.
3. What are the total water resources in our country?
Ans: Groundwater is the main source of water in India. Surface water, subterranean river flow, groundwater, and frozen water are all-natural freshwater sources. Treated wastewater and desalinated saltwater are examples of artificial freshwater sources.
4. Where is groundwater adequately available?
Ans: Groundwater is often hidden deep in aquifers, permeable rocks and sediments and is extracted using pumping wells. Often, aquifers can be renewable water resources, slowly replenished by rainfall infiltration over hundreds up to many thousands of years.
Short Type Questions Answer
1. What is the state of drinking water in India? Discuss.
Ans: Despite an extensive river system, safe clean drinking water as well as irrigation water supplies for sustainable agriculture are in shortage across India, in part because it has, as yet, harnessed a small fraction of its available and recoverable surface water resource.
2. Why is water scarcity experienced in the country though the resources are abundant?
Ans: Water scarcity is a worldwide crisis and is caused by a combination of issues resulting from rapid population growth and urbanisation, such as hydrological variabilities, overexploitation, and high human use.
3. Why do we face water scarcity today?
Ans: Water scarcity is a water shortage or stress. Water scarcity can be because of economic water scarcity or physical water scarcity. Physical scarcity of water is when natural water resources cannot meet a region’s demand, while financial water scarcity results from poor management of water resources.
4. How much water is available to us as fresh water?
Ans: The oceans constitute 97.3% of all water sources on the Earth. Thus, the percentage of freshwater sources is only 2.7%. Of all the freshwater sources, only 2.9% of it is available to us in the form of freshwater lakes, rivers, and groundwater.
Long Type Questions Answer
1. Describe the water resources in India and mention the surface water and the ground water resources.
Ans: These resources include both surface water and groundwater.
(i) Surface Water Resources:
(a) Reservoirs: Surface water and groundwater are reservoirs that can feed into each other. While surface water can seep underground to become groundwater, groundwater can resurface on land to replenish surface water. Springs are formed in these locations. There are three types of surface water: perennial, ephemeral, and artificial.
(b) Lakes and Ponds: A pond is a small body of water that is surrounded by land. Both are formed from retreating glaciers, tectonic movements, and volcanic activity. Most lakes are formed naturally, while ponds can be easily human made, such as for backyard ponds.
(ii) Groundwater Resources:
(a) Alluvial Plains: Geomorphologically, alluvial plains are the most vital and fertile landscapes used for high agricultural productivity (Verhoeven and Setter, 2009). Groundwater levels and quality always tend to vary, some changes are due to natural phenomena and some are induced because of mankind.
(b) Hard Rock Areas: The groundwater stored between layers of hard rock below the water table is called aquifer. An aquifer is a saturated zone beneath the water table. It is a body of porous rock or sediment saturated with groundwater.
(c) Over-Exploited Areas: Excessive pumping can lower the groundwater table, and cause wells to no longer be able to reach groundwater. Increased Costs. As the water table lowers, the water must be pumped farther to reach the surface, using more energy.
2. What is meant by irrigation? Why is it needed in India?
Ans: The artificial application of water to the soil or agricultural land which fulfils the demand for water is known as Irrigation.It is the process of replacing or supplementing rainwater with water from another source. It is used in dry places and when rainfall is insufficient. It enables farmers to produce crops in areas with low or irregular rainfall, increasing food security and economic stability. Irrigation systems are designed to aid in the growth of agricultural crops and plants by using the least amount of water possible, preventing soil consolidation, and so on. Irrigation frequency, rate, amount, and time differ for different crops, as well as soil types and seasons. Summer crops, for example, demand far more water than winter crops. However, overirrigation can lead to problems like waterlogging, salinization, and environmental degradation. Therefore, sustainable and efficient irrigation practices are essential to ensure long-term agricultural productivity and environmental balance.
The following are the needs of irrigation in India:
(i) India has traditionally been an agrarian economy, and about two-third of its population have been dependent on agriculture. Hence, development of irrigation is necessary to increase agricultural production.
(ii) Irrigation is needed because of spatio-temporal variability in rainfall in the country. The large tracts of the plains and agricultural lands are particularly dependent on irrigation.
(iii) Countries are deficient in rainfall and are drought prone. Winter and summer seasons are more or less dry in arid and semi-arid regions.
(iv) Most of the country. Assured irrigation during dry seasons can make farmers grow crops.
(v) Breaks in monsoon or its failure creates dry spells detrimental for agriculture. Irrigation can protect crops during failure of monsoon.
(vi) Water needs of certain crops also makes irrigation necessary. Water requirement of rice, sugarcane, jute, etc. is very high which can be met only through irrigation.
(vii) Provision of irrigation makes multiple cropping possible. It has also been found that irrigated lands have higher agricultural productivity than unirrigated land.
(viii) The high yielding varieties of crops need regular moisture supply, which is made possible only by developed irrigation systems. Punjab and Haryana have better irrigation facilities which was the reason for the success of Green Revolution.
3. Give a detailed account of irrigation by canals and wells.
Ans: Canal irrigation in India: Canal irrigation is one of the most important sources of irrigation for farmlands across India. It accounts for nearly 24% of the total irrigated land in the country. This effective source of irrigation has greatly benefited deep fertile soil, low-level relief, and perennial river areas. Canal irrigation is more prevalent in the northern plains as compared to other parts of the country. One of the reasons behind the decline of the prevalence of canal irrigation in India is the heavy maintenance required to ensure efficiency.
An irrigation canal is a hydraulic system whose main objective is to convey water from a source (dam and river) to different users.Such systems can be very large (several tens or hundreds of kilometres); they are characterised by time delays and nonlinear dynamics, strong unknown perturbations and interactions among subsystems. Varying operational objectives are assigned to their managers. The main general objective is to provide water to the different users at the right moment and in the right quantity, reducing losses as much as possible in order to guarantee the safety of the infrastructure. In particular, a major concern is to prevent the canals from overtopping, and also from having water levels inside the pools below the supply depths of the gravity offtakes.
Canals in India are regarded as a prominent source of irrigation in areas of low level relief, deep fertile soils, perennial source of water and an extensive area. This implies that the major concentration of canal irrigation in the northern plains of India consists of Uttar Pradesh, Punjab, Haryana, Rajasthan, Bihar, Andhra Pradesh, West Bengal, Madhya Pradesh, Chhattisgarh, Karnataka, Orissa and Tamil Nadu.
Well Irrigation:
(i) Well Irrigation is defined as any well constructed for the purpose of obtaining groundwater to supply irrigation water for agriculture, silviculture, golf courses, fish farms, and land beautification.
(ii) But household use of water is excluded i.e. single-family irrigation of lawns or gardens.
(iii) There are two types of well Irrigation – High flow and Low flow.
(iv) Low flow systems can be used to micro spray, drip emitters, or drip lines.etc.
4. Discuss the development of irrigation in India.
Ans: Irrigation in India includes a network of major and minor canals from Indian rivers, groundwater well based systems, tanks, and other rainwater harvesting projects for agricultural activities. Of these, the groundwater system is the largest.
Irrigation in India helps improve food security, reduce dependence on monsoons, improve agricultural productivity and create rural job opportunities. Dams used for irrigation projects help produce electricity and transport facilities, as well as provide drinking water supplies to a growing population, control floods and prevent droughts.
Some of the method of irrigation:
(i) Drip system: In this method, plants are watered drop by drop at their roots. It is the best irrigation method for crops and fruit- bearing plants. Pipes called ‘dripper lines’ having smaller units known as ‘drippers’ transport water and nutrients to the plants. Each dripper releases drops that contain water and fertilisers, resulting in a uniform distribution of water and nutrients directly to the root zone of the growing plant throughout the whole region. The system provides water to plants drop by drop ensuring that water is not wasted.
(ii) Central Location in Eastern Hemisphere: India is very favourably located in relation to Eurasia, Africa and Australia. It occupies a central position in the eastern hemisphere. India’s location has many economic advantages. It helped in establishing economic and cultural contacts with the East Asian countries. Moreover, it could establish close contact with Southeast and East Asia from the sea ports of the eastern coast. It is favourably located on the world’s highway of trade and commerce, both to the east and the west. There are some prominent air routes and sea routes passing through the Indian subcontinent.
(iii) Sprinkler system: In this system, perpendicular pipes, having rotating nozzles on top, are joined to the main pipeline at regular intervals. When water is allowed to flow through the main pipe under pressure with the help of a pump, it escapes from the rotating nozzles. It gets sprinkled on the crop as if it is raining. This method is most effective on uneven land where there is not enough water available. Modern methods of irrigation help us to use water economically. Also, it is not labour intensive and is more efficient.
Other Textual Questions & Answer
1. Choose the right answers of the following from the given options:
(i) Which one of the following types describes water as a resource?
(a) Abiotic resource.
(b) Non-renewable resource.
(c) Biotic resource.
(d) Cyclic resource.
Ans: (d) Cyclic resource.
(ii) Which one of the following rivers has the highest replenishable ground water resource in the country?
(a) The Indus.
(b) The Brahmaputra.
(c) The Ganga.
(d) The Godavari.
Ans: (a) Indus.
(iii) Which of the following figures in cubic kilometres correctly shows the total annual precipitation in India?
(a) 2,000
(b) 4,000
(c) 3,000
(d) 5,000
Ans: (c) 4000.
(iv) Which one of the following south Indian states has the highest ground water utilisation (in percent) of its total ground water potential?
(a) Tamil Nadu.
(b) Karnataka.
(c) Andhra Pradesh.
(d) Kerala.
Ans: (a) Tamil Nadu.
(v) The highest proportion of the total water used in the country is in which one of the following sectors?
(a) Agriculture.
(b) Industries.
(c) Domestic use.
(d) None of the above.
Ans: (a) Agriculture.
(vi) Among the river basins of the country the largest runoff is:
(a) The Ganga basin.
(b) The Brahmaputra basin.
(c) The Godavari basin.
(d) The Indus basin.
Ans: (b) The Brahmaputra basin.
(ii) Top three states in utilising potential groundwater resources are:
(a) Punjab, Haryana and Uttar Pradesh.
(b) Punjab, Rajasthan and Tamil Nadu.
(c) Rajasthan, Haryana and Tamil Nadu.
(d) U.P., Gujarat and Punjab.
Ans: (a) Punjab, Haryana and Uttar Pradesh.
(iii) Largest use of water resource in India is for:
(a) Drinking and domestic purposes.
(b) Irrigation.
(c) Hydroelectric power.
(d) Pisciculture.
Ans: (b) Irrigation.
(iv) Which chemical has concentrated in water in Bihar?
(a) Salinity.
(b) Salt.
(c) Arsenic.
(d) Fluoride.
Ans: (c) Arsenic.
(v) How much percent net sown area is irrigated in Punjab?
(a) 75%
(b) 85%
(c) 80%
(d) 65%
Ans: (b) 85%.
(vi) Which part of the river has good quality water?
(a) Plain.
(b) Valley.
(c) Delta.
(d) Mountain.
Ans: (d) Mountain.
(vii) How much of the earth is covered with water?
(a) 81%
(b) 61%
(c) 51%
(d) 71%
Ans: (d) 71%.
(viii) What is the share of India in the world’s water resources?
(a) 2%
(b) 4%
(c) 3%
(d) 1%
Ans: (b) 4%.
2. Give one word answer:
(i) Major source of surface water in India.
Ans: Rivers.
(ii) The dam from which Delhi gets its most of the potable water supply.
Ans: Tehri.
(iii) The project depends on the potable water supply in Chennai.
Ans: Telugu Ganga Project.
(iv) The river on which the Telugu Ganga Project is built.
Ans: Krishna.
(v) The water which flows a ‘run-off.
Ans: Surface water.
(vi) The type of soils facilitating easy percolation of water.
Ans: Alluvial.
(vii) The source of water supply on earth.
Ans: Precipitation.
(viii) The river basin with the largest run-off in India.
Ans: Brahmaputra Basin.
(ix) The state with the largest proportion of net irrigated area in the country.
Ans: Uttar Pradesh.
(x) The first irrigation canal in India.
Ans: Eastern Yamuna Canal.
(xi) The year of commissioning of the Eastern Yamuna canal.
Ans: 1882
(xii) The Indian village in Haryana, where the watershed development programme was implemented.
Ans: Sukhomajri Village.
(xiii) When was the Water Prevention Act passed?
Ans: in 1974.
(xiv) What is the name for a rain water harvesting pit?
Ans: Thanks.
(xv) State main aim of the National Water Policy.
Ans: To provide water for irrigation and drinking water.
(xvi) What is the total number of rivers in India?
Ans: 10360.
(xvii) Which three programmes have started under watershed management?
Ans: Hariyali, Neeru-Meeru, Aravary Pani Sansad.
(xviii) What do you mean by clean water?
Ans: When water is without unwanted foreign substances.
(xix) Which is the most polluted river in India?
Ans: Yamuna between Delhi and Etawah.
2. Answer the following questions in not more than 30 words:
(i) It is said that the water resources in India have been depleting very fast. Discuss the factors responsible for depletion of water resources.
Or
What are the main reasons of degradation of quality of water in India?
Or
Examine any three causes deterioration of the quality of water in India.
Or
Ans: The factors responsible for the depletion of water in India are as follows:
1. Industrial effluents.
2. Agricultural effluents.
3. Domestic effluents.
(ii) What factors are responsible for highest groundwater development in the states of Punjab, Haryana, and Tamil Nadu?
Ans: The ground water utilisation is very high in the states of Punjab, Haryana and Tamil Nadu. These states are advanced agricultural states. Water is used mainly in irrigation. The share of agriculture sector in total water utilisation is much higher than other sectors.
(iii) Why the share of agricultural sector in total water used in the country expected to decline?
Ans: The share of agricultural sector in tot because water used in the country is expected to decline because:
1. The industrial and domestic sectors in the country are likely to increase.
2. The total utilisable water resources are also Declining.
3. The overuse of groundwater resources has led to decline in the groundwater.
(iv) What can be the possible impacts of consuming contaminated/unclean water on the poor?
Ans: The use of unclean water badly affected the health of the poor. The contaminated water spread the water-born diseases such as diarrhoea, cholera and other stomach diseases.
