Roadmap for Answer Writing

1. Introduction

• • Start with a clear definition of a cloudburst.
  • Mention its characteristics (intense rainfall, small affected area, and short duration).
  • Briefly explain its consequences (flash floods, landslides, etc.).

2. Understanding Cloudburst Mechanism

• • Discuss the meteorological factors that lead to a cloudburst, specifically orographic lifting (mountains forcing moist air upwards).
  • Explain how the steep terrain of the Himalayas makes the region prone to such extreme weather events.

3. Reasons for Increasing Cloudbursts in the Himalayan States:

• • Orographic Lifting: Explain how mountains play a key role in the formation of cloudbursts.
  • Climate Change: Discuss how rising global temperatures and warming oceans contribute to increased moisture in the atmosphere.
  • Changing Wind Patterns: Explain the increasing convergence of warm monsoon winds and cool dry western winds, which results in the formation of low-pressure systems in the region.
  • Urbanization & Deforestation: Higher surface temperatures in valleys due to human activities (e.g., deforestation, urban expansion) contribute to cloudburst formation by creating an environment that holds more moisture.

4. Recent Cloudburst Incidents:

• • Provide two examples of recent cloudburst events:
    1. October 2023 – North Sikkim: Cloudburst over Lhonak Lake leading to a flash flood in the Teesta River (Lachen Valley).
    2. August 2023 – Himachal Pradesh: Cloudburst at Jadon village in Solan resulting in significant damages.

Conclusion

• • Summarize the causes of increasing cloudbursts in the Himalayan states.
  • Mention the need for policy measures to mitigate such extreme events, like better forecasting, forest conservation, and climate action.

Relevant Facts:

1. Cloudburst Definition:
   • According to the Indian Meteorological Department (IMD), cloudbursts are characterized by rainfall intensity exceeding 100 mm/hour within a short time span.
2. Orographic Lifting and Cloudbursts:
   • When warm moist air from the monsoon season encounters the Himalayan mountains, it is forced upwards (orographic lifting), resulting in the formation of cumulonimbus clouds which cause intense rainfall.
3. Climate Change:
   • Ocean warming due to climate change increases the moisture in the atmosphere, leading to more frequent cloudbursts. Additionally, higher global temperatures contribute to increased land surface temperatures, making the region more prone to such extreme weather events.
4. Recent Incidents:
   • October 2023 – North Sikkim: Cloudburst over Lhonak Lake led to flash floods in Teesta River, impacting Lachen Valley .
   • August 2023 – Himachal Pradesh: A cloudburst in Jadon village, Solan, caused significant damage.
5. Deforestation and Urbanization:
   • Deforestation and urbanization in the Himalayan valleys increase surface temperatures, which enhances the air’s ability to hold moisture, leading to an increased risk of cloudbursts.