Water Resources
Chapter 3
EXERCISES
Answer: Suffering from water scarcity.
Answer: Suffering from water scarcity.
Answer: Multipurpose projects result in large-scale displacement and loss of livelihoods.
Answer: Multiplying urban centres with large and dense populations and urban lifestyles have caused the over exploitation of water resources.
(b) Multi-purpose projects by regulating water flow helps to control floods.
Answer: Regulating and damming of rivers affect their natural flow and causes the sediment to settle at the bottom of the reservoir.
(c) Multi-purpose projects lead to large scale displacements and loss of
livelihood.
Answer: Farmers in the Sabarmati basin were agitated when water supply in urban areas was given higher priority in Gujarat, especially during drought.
(d) Multi-purpose projects generate electricity for our industries and our
homes.
Answer: Today in Rajasthan, the practice of rooftop rainwater harvesting is on the decline due to the Rajasthan canal.
(iii) Here are some false statements. Identify the mistakes and rewrite them
correctly.
(a) Multiplying urban centres with large and dense populations and urban
lifestyles have helped in proper utilisation of water resources.
Answer: Statement 1 is false.
(b) Regulating and damming of rivers does not affect the river’s natural
flow and its sediment flow.
Answer: Statement 1,2 and 3 are false.
(c) In Gujarat, the Sabarmati basin farmers were not agitated when higher
priority was given to water supply in urban areas, particularly during
droughts.
Answer: All statements are false.
(d) Today in Rajasthan, the practice of rooftop rainwater water harvesting
has gained popularity despite high water availability due to the Indira
Gandhi Canal.
Answer: Both Statement 1 and 2 are false.
2 . Answer the following questions in about 30 words.
(i) Explain how water becomes a renewable resource.
Answer: All the water used initially ends up in the sea. From there, it enters the hydrology cycle in the form of water vapor. Freshwater is renewed by this cycle when it rains. Therefore, water is a renewable resource.
(ii) What is water scarcity and what are its main causes?
Answer: There is water scarcity or water stress when the availability of water is not sufficient to match the demand for water. This is due to population growth, rising demand for water, and unequal access to it.
(iii) Compare the advantages and disadvantages of multi-purpose river projects.
Answer: The multipurpose river project helps in irrigation, power generation, flood control, internal navigation and fish breeding. However, water bodies destroy native plants and animals. Many local villages have been inundated, and people have lost their livelihoods, with little or no hope of rehabilitation.
3 . Answer the following questions in about 120 words.
(i) Discuss how rainwater harvesting in semi-arid regions of Rajasthan is carried out.
Answer: Households in the semi-arid regions of Rajasthan have traditionally built tanks to store drinking water. They are part of the large and well-developed roof rainwater harvesting system. The tanks are built inside the main house or choral, and are connected to the tilted roof of the houses through pipes. Falling on the roof moves in the rain and is stored in the tanks. The first drop of rain is not collected as this water cleans the roofs and pipes. Rainwater is collected from the next mantra. This water is used until the next rainy season, and is a reliable source of water even after other sources have dried up. The tanks help cool the houses as the rooms built around them usually have lower temperatures for transportation.
(ii) Describe how modern adaptations of traditional rainwater harvesting methods are being carried out to conserve and store water.
Answer: Traditional methods of rainwater harvesting such as the 'rooftop method' have become popular in India. In Gendathur village of Mysuru, around 200 families have adopted rooftop rainwater harvesting methods, making the village rich in rainwater. The state of Tamil Nadu has made it mandatory for all households to have rooftop rainwater harvesting structures. Defaulters are severely punished.
