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
Cloudburst FAQs
Q1: What is a Cloudburst?
Ans: A cloudburst is an extremely intense rainfall event, usually localised, where more than 100 mm of rain may fall in an hour, often leading to flash floods.
Q2: Where are cloudbursts most common in India?
Ans: They frequently occur in the Himalayan regions, especially in Uttarakhand, Himachal Pradesh, and Jammu & Kashmir, due to orographic lift and weather instability.
Q3: What causes a cloudburst?
Ans: It results from the sudden condensation of moisture-laden clouds, often enhanced by topography and local convergence zones.
