Q6. What is the phenomenon of ‘cloudbursts’? Explain. (10M)

Introduction

A cl*oudburst is an intense and sudden rainfall event, typically localized to a small area, resulting in heavy downpours within a short period. The rainfall rate during a cloudburst often exceeds 100 mm per hour,* sometimes causing flash floods and landslides, especially in hilly or mountainous regions.

Mechanism of Cloudbursts: Cloudbursts occur when warm, moist air rapidly rises due to convection. As the air ascends, it cools, and the moisture condenses to form clouds. In certain conditions, particularly in regions with steep topography, the clouds are unable to release moisture gradually, leading to the sudden and concentrated release of rain. Factors contributing to cloudbursts include:

• Orographic Lift: In mountainous areas, air masses are forced upwards when they encounter hills or mountains. This increases condensation and can lead to the rapid release of rain. E.g. Leh cloudburst in 2010 Temperature Differences: Sharp contrasts in temperature can lead to strong upward air currents, which trap moisture in the clouds, eventually leading to a cloudburst. E.g. In Leh, Ladakh (2022), a cloudburst occurred due to a temperature-induced thunderstorm. Localized Thunderstorms: Thunderstorms that develop due to intense heating can also trigger cloudbursts, with localized areas experiencing intense downpours. E.g. In July 2021, a cloudburst near Amarnath Cave in Jammu and Kashmir

• E.g. Leh cloudburst in 2010

• Temperature Differences: Sharp contrasts in temperature can lead to strong upward air currents, which trap moisture in the clouds, eventually leading to a cloudburst. E.g. In Leh, Ladakh (2022), a cloudburst occurred due to a temperature-induced thunderstorm.

• E.g. In Leh, Ladakh (2022), a cloudburst occurred due to a temperature-induced thunderstorm.

• Localized Thunderstorms: Thunderstorms that develop due to intense heating can also trigger cloudbursts, with localized areas experiencing intense downpours. E.g. In July 2021, a cloudburst near Amarnath Cave in Jammu and Kashmir

• E.g. In July 2021, a cloudburst near Amarnath Cave in Jammu and Kashmir

Effects of Cloudbursts:

• Flash Floods: Cloudbursts can cause flash floods because the intense rainfall overwhelms drainage systems and quickly floods rivers and streams. g. In Chamoli, Uttarakhand (August 2023), a cloudburst caused flash floods that washed away several homes and livestock.

• g. In Chamoli, Uttarakhand (August 2023), a cloudburst caused flash floods that washed away several homes and livestock.

• Landslides: In mountainous regions, cloudbursts often trigger landslides. Heavy rain loosens the soil, rocks, and vegetation on slopes, causing debris to slide downhill. g. In Shimla, Himachal Pradesh (August 2023), a cloudburst triggered landslides that buried houses and roads under debris.

• g. In Shimla, Himachal Pradesh (August 2023), a cloudburst triggered landslides that buried houses and roads under debris.

• Casualties and Property Damage: Due to the intense nature of cloudbursts, they often result in significant loss of life and destruction of infrastructure, particularly in underdeveloped areas with poor drainage and flood management systems. g. In Himachal Pradesh (July 2023), a cloudburst triggered by orographic lifting caused flash floods and landslides in the Kullu and Mandi districts.

• g. In Himachal Pradesh (July 2023), a cloudburst triggered by orographic lifting caused flash floods and landslides in the Kullu and Mandi districts.

Conclusion

Cloudbursts have become a significant concern in the Indian subcontinent, due to changing climate patterns and increasing human habitation in vulnerable areas and there is a need for robust urban planning and sustainable infrastructure development strategies to minimize damage.