Test: Water Resources - 2 - Class 10 MCQ

Water covers about 71% of the Earth's surface, which includes both saltwater and freshwater bodies. This significant coverage highlights the abundance of water on the planet, although only a small portion is freshwater available for human use.

• The Jal Jeevan Mission (JJM) primarily aims to ensure that every rural household has access to a reliable supply of clean piped water.
• It targets a provision of 55 liters per person per day.
• This initiative is crucial for improving the quality of life in rural areas, where access to potable water has historically been a challenge.
• An interesting fact is that the JJM not only addresses water scarcity but also aims to enhance water quality by ensuring that the supplied water is free from contamination.
• This is vital for public health.

• The Assertion (A) is true because it accurately reflects the situation of water scarcity in many regions, where over-exploitation by agriculture, industrial use, and unequal access among societal groups contributes significantly to the problem.
• The Reason (R) is also true, as the hydrological cycle does indeed provide avenues for the replenishment of freshwater through natural processes.
• However, it does not accurately explain why water scarcity occurs.
• Just because water can be replenished through these natural processes does not negate the issue of over-exploitation and access disparities that lead to scarcity.
• Therefore, while both statements are true, the Reason does not serve as the correct explanation for the Assertion.
• Hence, the correct answer is Option B.

• A Flood Control Dam is primarily constructed to manage and mitigate flood risks.
• It can paradoxically contribute to flooding if sediment builds up in the reservoir, reducing its capacity to hold water.
• This phenomenon can occur during excessive rainfall when the dam's ability to regulate water flow is compromised.
• An interesting fact is that while dams are crucial for flood management, they can also disrupt local ecosystems and the natural flow of rivers, leading to significant ecological changes.

Controlling water flow is the main purpose of a dam. It serves to obstruct, direct, or retard the flow of water, which allows for the creation of reservoirs or lakes that can be used for various purposes such as irrigation, electricity generation, and flood control.

• Option A: Bhakra-Nangal Dam - Flood Control
  • This is incorrect. The Bhakra-Nangal Dam is primarily used for hydropower production and irrigation, not specifically for flood control.
• Option B: Hirakud Dam - Irrigation
  • This is incorrect. While Hirakud Dam does provide irrigation benefits, it is most notably used for flood control in the Mahanadi basin.
• Option C: Bhakra-Nangal Dam - Hydel Power Production
  • This is correct. The Bhakra-Nangal Dam, located in the Sutlej-Beas River Basin, is widely used for hydropower production and irrigation purposes.
• Option D: Hirakud Dam - Recreational Purposes
  • This is incorrect. The Hirakud Dam is used primarily for flood control, although it may have some secondary recreational uses, this is not its main purpose.
• Therefore, the correctly matched pair is Option C: Bhakra-Nangal Dam - Hydel Power Production.

• The traditional method of water collection in semi-arid regions of Rajasthan involves the use of underground rainwater tanks, known as 'tankas.'
• These tanks are specifically designed to collect and store rainwater from rooftops, ensuring a reliable water supply during dry periods.
• The design aids in maximizing water conservation, as rainwater is collected after the initial rainfall, which cleans the roofs and pipes.
• This practice is crucial for communities in arid environments, allowing them to manage scarce water resources effectively.
• Interestingly, rainwater harvested in this manner is often regarded as the purest form of natural water, making it a preferred source for drinking during hot summer months.

Rainwater Harvesting refers to the process of collecting and storing rainwater for later use, rather than letting it run off into drains or water bodies. This practice is crucial for sustainable water management, especially in regions facing water scarcity.

• The Assertion is true because rainwater harvesting systems are indeed crucial in conserving water, particularly in regions that experience low rainfall and high water scarcity.
• The Reason is also true, as the traditional underground tanks ('tankas') in Rajasthan play a vital role in storing rainwater, thus providing a reliable source of drinking water during periods of drought.
• Furthermore, the Reason serves as a correct explanation for the Assertion, as it highlights the practical application of rainwater harvesting in addressing water conservation needs in arid regions.

• Option A: Rooftop Rainwater Harvesting - Tamil Nadu: This is incorrect. While Tamil Nadu has made rooftop rainwater harvesting compulsory, the state is not the only example of rooftop rainwater harvesting. Other states also practice it, but this pair does not uniquely match Tamil Nadu.
• Option B: Bamboo Drip Irrigation - Rajasthan: This is incorrect. Bamboo Drip Irrigation is a traditional practice in Meghalaya, not Rajasthan. Rajasthan is known for its underground tankas for rainwater harvesting.
• Option C: Rooftop Rainwater Harvesting - Meghalaya: This is correct. Rooftop rainwater harvesting is a common practice in Shillong, Meghalaya, where nearly every household has such a structure to meet a part of their water requirements.
• Option D: Bamboo Drip Irrigation - Kerala: This is incorrect. Bamboo Drip Irrigation is a traditional system prevalent in Meghalaya, not Kerala.
• Thus, the correctly matched pair is Option C: (c) Rooftop Rainwater Harvesting - Meghalaya.