Test: Water Resources - 1 - UPSC

The water covered surface of the Earth is three-fourth.
Explanation:
- The Earth is primarily composed of water and land.
- The water covered surface of the Earth refers to the area that is covered by water bodies such as oceans, seas, lakes, and rivers.
- To determine the percentage of the water covered surface, we need to compare it to the total surface area of the Earth.
- The Earth has a total surface area of approximately 510 million square kilometers.
- The total area covered by water bodies is estimated to be about 361 million square kilometers.
- To find the percentage, we divide the area covered by water by the total surface area of the Earth and multiply by 100.
- (361 million sq km / 510 million sq km) x 100 = 70.78%
- Therefore, the water covered surface of the Earth is approximately three-fourth or 70.78% of the total surface area.
- This means that only about one-fourth or 29.22% of the Earth's surface is covered by land.
- So the correct answer is B: three-fourth.

Not the cause of water scarcity:


Rapid growth of population:
- Rapid population growth can lead to increased water demand, putting pressure on available water resources.
- As the population increases, the demand for water also increases, which can contribute to water scarcity.
Uneven distribution of water resources:
- Uneven distribution of water resources is a significant cause of water scarcity.
- Some regions may have abundant water resources, while others may face water scarcity due to limited availability.
Construction of dams and reservoirs:
- Construction of dams and reservoirs can actually help in managing water supply and reducing water scarcity.
- Dams and reservoirs store water, which can be used during dry periods and help regulate water flow.
Increase in demand:
- Increase in demand for water is a major cause of water scarcity.
- As the population grows and industries expand, the demand for water also increases, leading to water scarcity in some areas.
Conclusion:
- Among the given options, the construction of dams and reservoirs is not a cause of water scarcity.
- Dams and reservoirs are actually built to manage water resources and alleviate water scarcity in certain regions.

About 97.3% of Earth's total volume of water is found in the ocean. As per the given Options, Option (1) is the most appropriate answer.

Important Points

• The Earth's surface is covered with 71 percent of water due to which it is also known as the blue planet.
• Around 97% of the earth's water is found in the oceans
• But it is too salty for drinking, growing crops, and most industrial uses except cooling
• The water in the ocean contains dissolved salt which is unfit for drinking.
• Most of the salt found in the ocean is sodium chloride.
• The average salinity of the oceans is 35 parts per thousand.

The percentage of freshwater resources on Earth
- The Earth is composed mostly of water, with approximately 71% of its surface covered by oceans, seas, and other bodies of saltwater.
- However, freshwater resources, which are essential for human consumption and various other purposes, only make up a small percentage of this total water supply.
- The correct answer is 2.5% (C).
- Here is a detailed explanation of why this is the correct answer:
1. Definition of freshwater:
- Freshwater refers to water that contains a low concentration of dissolved salts.
- It is found in lakes, rivers, underground aquifers, and frozen in glaciers and ice caps.
2. Distribution of Earth's water:
- About 97.5% of the Earth's water is in the form of saltwater, primarily in the oceans.
- Only about 2.5% of the Earth's water is freshwater.
3. Breakdown of freshwater:
- Out of this 2.5% of freshwater, the majority is locked in glaciers and ice caps, making it inaccessible for direct use.
- The remaining freshwater is available in accessible forms such as groundwater, lakes, rivers, and atmospheric water vapor.
4. Availability of usable freshwater:
- Not all of the accessible freshwater is available for immediate use due to various factors such as contamination, seasonal variations, and uneven distribution.
- Of the accessible freshwater, only a small fraction is considered usable for human consumption and other purposes.
5. Conclusion:
- In conclusion, although the Earth is mostly occupied by water, the percentage of usable freshwater resources is relatively low.
- The correct answer to the given question is 2.5% (C), as this represents the proportion of freshwater resources in relation to the total water supply on Earth.

Answer:
The state that has made rooftop rainwater harvesting structure compulsory to all houses across the state is Tamil Nadu.
Reason:
Tamil Nadu is known for its efforts in water conservation and management. The state government has taken several initiatives to address the water scarcity issue, and one of them is making rooftop rainwater harvesting mandatory for all houses.
Benefits of rooftop rainwater harvesting:
- Helps in replenishing groundwater levels: By collecting rainwater and redirecting it to underground storage tanks, rooftop rainwater harvesting helps recharge the groundwater levels, which in turn prevents the depletion of water resources.
- Reduces dependency on external water sources: With rooftop rainwater harvesting, households can rely on rainwater for various purposes like gardening, washing, and even drinking water. This reduces the burden on external water sources and promotes self-sufficiency.
- Mitigates the impact of drought: Tamil Nadu is prone to droughts, and rooftop rainwater harvesting provides a sustainable solution to combat the effects of drought by conserving rainwater during the monsoon season.
- Cost-effective and eco-friendly: Implementing rooftop rainwater harvesting is a cost-effective and eco-friendly method as it does not require the installation of complex infrastructure or dependence on energy-consuming water supply systems.
Steps taken by Tamil Nadu government:
- The Tamil Nadu government has made it compulsory for all new buildings to have rooftop rainwater harvesting structures.
- Existing buildings are also required to retrofit rainwater harvesting systems within a specified timeframe.
- The government has provided subsidies and financial incentives to encourage households to adopt rainwater harvesting.
- The Tamil Nadu Water Supply and Drainage Board (TWAD) has been actively promoting and implementing rainwater harvesting projects across the state.
Therefore, Tamil Nadu has taken significant steps to ensure the widespread implementation of rooftop rainwater harvesting structures to combat water scarcity and promote sustainable water management.

Rank of India in the world in terms of water availability per person per annum:
India's rank in terms of water availability per person per annum is 133.
Explanation:
- According to the World Bank, water availability is measured in cubic meters per person per year.
- The water availability per person in India is relatively low compared to other countries.
- India receives an average annual rainfall of about 4,000 billion cubic meters, but due to population size and inefficient water management, the per capita availability is low.
- The water scarcity in India is mainly due to uneven distribution, overexploitation of groundwater, and inadequate infrastructure for water storage and distribution.
- The low availability of water per person has significant implications for agriculture, domestic use, and industrial activities in the country.
- The ranking of countries in terms of water availability per person per annum is determined by comparing the water resources and population of each country.
- India's rank of 133 indicates that there are 132 other countries in the world with better water availability per person.
- It highlights the need for sustainable water management practices and efficient utilization of water resources in India.
Therefore, the correct answer is option C: 133 rank.

Dams are huge water retaining structures. These are used to store water. During the season of low rainfall, the storage water can be used for agricultural purposes. This stored water is also helpful in case of fish agriculture. Due two huge storage of water, it passes down to underground water streams and increases the water level. Subsequently this increased water level increases the water content in Wells of nearby villages

Hydraulic structures in Ancient India:
- Bhopal Lake: Bhopal Lake, also known as Upper Lake, is an artificial lake in Bhopal, Madhya Pradesh, India. It was built in the 11th century by Raja Bhoj. The lake acts as a major source of water supply for the city of Bhopal.
- Lake Hauz Kauz: Lake Hauz Kauz, located in Delhi, was constructed in the 13th century by Sultan Alauddin Khalji. It served as a water reservoir to supply water to the nearby areas.
- Construction of dams, lakes: Ancient India witnessed the construction of numerous dams and lakes to manage and store water for agricultural purposes. These hydraulic structures were built to ensure water availability during dry seasons and to control floods during the monsoon.
Not an example of Hydraulic structure:
- Damodar Valley Project: The Damodar Valley Project is a multipurpose river valley project in India. It was initiated in the mid-20th century for flood control, irrigation, and power generation. Therefore, it does not fall under the category of hydraulic structures in ancient India.
In conclusion, the Damodar Valley Project is not an example of hydraulic structures in ancient India. It was a modern project established in the mid-20th century, while the other options mentioned (Bhopal Lake, Lake Hauz Kauz, and construction of dams, lakes) are examples of ancient hydraulic structures in India.

Hydroelectric Power Contribution in India's Total Electricity Production
India has a significant contribution of hydroelectric power in its total electricity production. Let's analyze the details:
1. Total Electricity Production in India:
- India's total electricity production is a combination of various sources such as thermal, hydro, nuclear, and renewable energy.
- The country has been making efforts to increase the share of renewable energy sources in its total electricity production.
2. Contribution of Hydroelectric Power:
- Hydroelectric power is generated by harnessing the energy of flowing or falling water.
- India has abundant water resources, which makes hydroelectric power a valuable source of renewable energy.
- Hydroelectric power plants are installed across several rivers and dams in the country.
3. Percentage Contribution:
- According to recent data, approximately 22 per cent of India's total electricity production is contributed by hydroelectric power.
- This means that out of the entire electricity generated in India, around 22 per cent comes from hydroelectric plants.
4. Importance of Hydroelectric Power:
- Hydroelectric power is considered a clean and renewable source of energy.
- It helps in reducing greenhouse gas emissions and dependence on fossil fuels.
- Hydroelectric projects also contribute to irrigation, flood control, and overall water management.
Therefore, the correct answer is option A: Approximately 22 per cent of the total electricity produced in India is contributed by hydroelectric power.

There are two main sources of water: surface water and groundwater. Surface Water is found in lakes, rivers, and reservoirs. Groundwater lies under the surface of the land, where it travels through and fills openings in the rocks. The rocks that store and transmit groundwater are called aquifers.