Cloudburst

Cloudburst Latest News

Recently, the Ramban district of Jammu and Kashmir witnessed torrential rainfall and hail, resulting in severe damage.

• The India Meteorological Department (IMD) reported 16.9 mm of rainfall in 24 hours, marking a 575% increase from the normal 2.5 mm.

What is a Cloudburst?

• A cloudburst is a localised and extremely intense rainfall event, defined by rainfall of 10 cm or more within one hour over an area of approximately 10 km × 10 km.
• Even 5 cm of rain in 30 minutes over the same area qualifies as a cloudburst.
• Cloudbursts are more common in mountainous regions due to a process known as orographic lift. In this phenomenon:
  • Warm air ascends the mountain slope and expands due to lower atmospheric pressure at higher altitudes.
  • As it expands and cools, the air releases its moisture in the form of precipitation.
  • When large volumes of warm, moist air keep rising and accumulating moisture without releasing it, it can lead to a sudden, violent downpour.
• Because of their localised nature, cloudbursts are difficult to forecast and can overwhelm drainage systems, resulting in flash floods and landslides.

What is a Flash Flood?

• A flash flood is a sudden and rapid inundation that occurs when excessive rainwater enters streams, drains, or rivers, often overwhelming the natural or built drainage capacity.
• These are more frequent in mountainous regions where the rocky terrain absorbs little water, causing more surface runoff.
• Unlike riverine floods in plains that cause long-term property damage, flash floods tend to be more deadly, often catching people off guard and leading to loss of life.

What is a Landslide?

• A landslide refers to the movement of rock, debris, or earth down a slope, typically triggered when the force of gravity exceeds the resisting strength of the slope.
• Heavy rainfall plays a critical role in causing landslides by:
  • Increasing the weight of the slope material.
  • Reducing cohesion and friction, which makes it easier for soil and rocks to slide.
• Water infiltration from intense rain destabilises the slope, making landslides more likely.
• Landslides can:
  • Crush living beings under debris.
  • Disrupt roads and transportation.
  • Block rivers, potentially causing secondary flooding.

Source: IE

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