UPSC Mains Daily Answer Writing - 2 November (GS 3)

Questions

1. Dam failures are always catastrophic, especially on the downside side, resulting in a colossal loss of life and property. Analyze the various causes of dam failures. Give two examples of large dam failures. (10)

2. What is oil pollution? What are its impacts on the marine ecosystem? In what ways is oil pollution particularly harmful for a country like India. (10)

Model Solutions

Q1. Dam failures are always catastrophic, especially on the downside side, resulting in a colossal loss of life and property. Analyze the various causes of dam failures. Give two examples of large dam failures. (10)

Core Demand- Important keywords include loss of life and property. In this answer you need to majorly focus on Causes and write 2 examples of large dam failures. It's a 10 marker so you won't have enough space to discuss about Impact, way forward etc.

Model Structure
Introduction:

• Generic explanation based: A dam failure is simply an uncontrolled release of water from a reservoir through a dam as a result of structural failures or deficiencies in the dam.
• Current affairs: More than 11,000 people have been killed and tens of thousands are missing following the catastrophic collapse of two dams in eastern Libya.
• Research/ Report based- In a 2021 U.N. report, a team of experts studied over 50,000 big dams worldwide. They discovered that many of these dams are over 50 years old and face a growing risk of breaking.

Main Body:
Causes of dam failures

• Flood event
• Inadequate spillway
• Foundation problems
• Poor construction
• Siltation
• Ageing infrastructure and poor maintenance
• Uneven settlement: A site for a dam will not always be level because dams are built in mountain areas, but the designers must take that into consideration.
• Hydroelectric power generation: Higher generation of hydroelectric power poses challenges to reservoir management and the likelihood of dam breaks.
• Rare causes:
  • Acts of war Eg: collapse of Ukraine’s Kakhovka dam
  • Defective material
  • Earthquakes

Ways to avoid dam failures

• Coordination between meteorologists and the staff responsible for the management of dams. For eg: Information about heavy rainfall.
• Regular inspection programme that takes into consideration all parts of the dam.
• Instruments for monitoring cracks in a dam’s walls and any changes in its structure
• Protection dam can be built downstream to secure the safety of the downstream area and its population.
• The areas downstream from the dams should be well planned for housing and other developments
  Examples of large dam failures

1. Machchhu dam, 1979 ,Gujarat:
   1. The failure was caused by excessive rain and massive flooding leading to the disintegration of the earthen walls of the four kilometre long Machchhu-2 dam
   2. It destroyed buildings, killed livestock and took lives(estimates range from 1,800 to as high as 25,000)
2. The Banqiao Dam, 1975, China:
   1. Heavy rains led to extreme flooding, with a year's worth of rain falling in 24 hours. A chain reaction caused 61 other reservoirs to collapse, releasing six billion cubic meters of floodwater.
   2. This affected an area equal to 10,000 square kilometers and resulted in 171,000 to 230,000 deaths from the flood, epidemics, and famine."
      Some more dam failures( for reference)
3. Sayano–Shushenskaya Dam, Russia: A turbine in the Sayano–Shushenskaya dam in Khakassia, Russia broke apart violently on August 17, 2009, causing significant damage.
4. The Tenton dam, United States near Idaho Falls, failed completely on June 5, 1976, releasing the contents of its reservoir.

Conclusion:

• Conclude by suggesting some way forward like regular monitoring and inspection

Q2. What is oil pollution? What are its impacts on the marine ecosystem? In what ways is oil pollution particularly harmful for a country like India. (10)

Core Demand: 3 subparts- 1- Oil Pollution, 2- Impact on marine ecosystem 3- Harmful impact on India. You can start by oil pollution in the intro itself for best utilisation of space.

Introduction:

• Explain Oil pollution

  • Oil pollution can be caused by any spillage of crude oil or its refined products. However, the largest and most damaging pollution events usually involve
    • Spills of petroleum or heavy bunker fuel from disabled tankers
    • Drill platforms at sea
    • From barges or ships on major inland waterways
    • From blowouts of wells or broken pipelines on land.

• Contextual/Example based- Oil spill from the MV Wakashio vessel off Mauritius, 2020

Main Body:
Impact on marine ecosystem

• Impact on coral reefs: Oil forms a thick and sticky layer on the water's surface, which can block sunlight from penetrating into the ocean.
• Damage to fishes:. Oil exposure can harm adult fish, causing issues like slow growth, liver problems, and reproductive difficulties. Fish eggs and young fish are even more sensitive to oil's harmful effects.
  • Oil can make fish and shellfish unsafe for humans to eat.
• Death of marine animals and birds- Oil damages fur and feathers, leaving animals like sea otters and birds vulnerable to the cold. Without protection from the cold water, they can die from hypothermia.
• Affects the entire food chain as oil spills disrupts photosynthesis in aquatic plants and phytoplankton.
• Oil pollution becomes an ecological disaster- Oil contains toxic compounds that harm marine life. When ingested or absorbed by organisms, it can lead to cellular damage, disrupt metabolic processes, and cause mutations.

Harmful for a country like India- Reasons

• Vast coastline- approx 7516 km including the mainland coastline as well as the island coastline.
• High Imports of oil makes it vulnerable to oil pollution- In the year 2020-21, over 84 per cent of India’s petroleum product demand (crude oil and petroleum products) was met through imports
• Risk to rich biodiversity: India's coastline is rich in biodiversity, hosting diverse marine life, including numerous species of fish, turtles, and dolphins
• India has extensive mangrove ecosystems and oil spill can damage this
• Economic impact on Fishermen community and marine tourism

Conclusion:
You can conclude by writing India’s response to oil pollution

• The Indian Coast Guard is the key authority in India for coordinating responses to oil spills in its maritime areas, according to the National Oil Spill Disaster Contingency Plan (NOSDCP).
• India quickly adopted the International Convention on Oil Pollution Preparedness, Response, and Cooperation (OPRC) in 1990, showing its commitment to addressing oil spills.

Next Post