WATER RESOURCES - Q&A
1. Multiple choice questions.
(i) Based on the information given below classify each of the situations as 'suffering from water scarcity' or 'not suffering from water scarcity'.
(a) Region with high annual rainfall.
(b) Region having high annual rainfall and large population.
(c) Region having high annual rainfall but water is highly polluted.
(d) Region having low rainfall and low population.
Answer:
(a) Not suffering from water scarcity (Explanation: Ample water availability usually prevents scarcity).
(b) [cite_start]Suffering from water scarcity (Explanation: A large population requires more water for domestic use and food production, leading to depletion even with high rainfall [cite: 752]).
(c) [cite_start]Suffering from water scarcity (Explanation: Even with ample water, scarcity may be due to bad quality of water polluted by wastes and chemicals, making it hazardous for use [cite: 785, 786]).
(d) Not suffering from water scarcity (Explanation: While rainfall is low, the low population means demand is likely managed, avoiding the "over-exploitation" that defines scarcity in the text context).
(ii) Which one of the following statements is not an argument in favour of multi-purpose river projects?
(a) Multi-purpose projects bring water to those areas which suffer from water scarcity.
(b) Multi-purpose projects by regulating water flow helps to control floods.
(c) Multi-purpose projects lead to large scale displacements and loss of livelihood.
(d) Multi-purpose projects generate electricity for our industries and our homes.
Answer: (c) Multi-purpose projects lead to large scale displacements and loss of livelihood.
[cite_start]Explanation: Options (a), (b), and (d) describe the intended benefits (irrigation, flood control, electricity)[cite: 809]. [cite_start]Option (c) describes a negative consequence/opposition to these projects[cite: 829].
(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.
(b) Regulating and damming of rivers does not affect the river's natural flow and its sediment flow.
(c) Today in Rajasthan, the practice of rooftop rainwater water harvesting has gained popularity despite high water availability due to the Indira Gandhi Canal.
Answer:
(a) Mistake: "helped in proper utilisation of water resources."
[cite_start]Corrected Statement: Multiplying urban centres with large and dense populations and urban lifestyles have not only added to water and energy requirements but have further aggravated the problem[cite: 773].
(b) Mistake: "does not affect the river's natural flow and its sediment flow."
[cite_start]Corrected Statement: Regulating and damming of rivers affect their natural flow causing poor sediment flow and excessive sedimentation at the bottom of the reservoir[cite: 830].
(c) Mistake: "has gained popularity"
[cite_start]Corrected Statement: Today in western Rajasthan, sadly the practice of rooftop rainwater harvesting is on the decline as plenty of water is available due to the perennial Indira Gandhi Canal[cite: 1032].
2. Answer the following questions in about 30 words.
(i) Explain how water becomes a renewable resource.
Answer: [cite_start]Freshwater is continually being renewed and recharged through the hydrological cycle[cite: 737]. [cite_start]All water moves within the hydrological cycle (evaporation, condensation, and precipitation) ensuring that water is a renewable resource[cite: 738].
(ii) What is water scarcity and what are its main causes?
Answer: Water scarcity refers to the shortage of water to meet demands. [cite_start]It is mainly caused by over-exploitation, excessive use, and unequal access to water among different social groups[cite: 747]. [cite_start]Large populations requiring more food and domestic water, as well as industrialization and urbanization, also contribute to it[cite: 752, 771].
(iii) Compare the advantages and disadvantages of multi-purpose river projects.
Answer:
[cite_start]Advantages: They integrate irrigation, electricity generation, water supply for domestic and industrial uses, flood control, recreation, inland navigation, and fish breeding[cite: 809].
[cite_start]Disadvantages: They affect the natural flow of rivers causing poor sediment flow and excessive sedimentation[cite: 830]. [cite_start]They fragment rivers making migration difficult for aquatic life [cite: 831][cite_start], submerge existing vegetation [cite: 832][cite_start], and can induce earthquakes and water-borne diseases[cite: 848].
3. Answer the following questions in about 120 words.
(i) Discuss how rainwater harvesting in semi-arid regions of Rajasthan is carried out.
Answer: [cite_start]In the semi-arid and arid regions of Rajasthan, particularly in Bikaner, Phalodi, and Barmer, almost all houses traditionally had underground tanks or 'tankas' for storing drinking water[cite: 967]. [cite_start]The tanks were built inside the main house or courtyard and were connected to the sloping roofs of the houses through a pipe[cite: 999, 1000]. [cite_start]Rain falling on the rooftops would travel down the pipe and be stored in these underground 'tankas'[cite: 1001]. [cite_start]The first spell of rain was usually not collected to clean the roofs and pipes[cite: 1002]. [cite_start]The rainwater, called 'palar pani', is considered the purest form of natural water[cite: 1011]. [cite_start]Many houses also constructed underground rooms adjoining the 'tanka' to beat the summer heat[cite: 1012].
(ii) Describe how modern adaptations of traditional rainwater harvesting methods are being carried out to conserve and store water.
Answer: Traditional rainwater harvesting methods are being adapted in modern times to combat water scarcity. [cite_start]For example, in Gendathur, a remote village in Mysuru, Karnataka, villagers have installed rooftop rainwater harvesting systems in their households to meet water needs[cite: 1034]. [cite_start]Using PVC pipes, rooftop rainwater is collected and filtered using sand and bricks, then directed to underground sumps for immediate usage or to recharge dug wells[cite: 1013, 1014]. [cite_start]This system has made the village rich in rainwater[cite: 1035]. [cite_start]Furthermore, states like Tamil Nadu have made rooftop rainwater harvesting structures compulsory for all houses across the state, with legal provisions to punish defaulters, ensuring widespread adoption of these conservation techniques[cite: 1044, 1045].