Cloudburst in Ramban District

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The Ramban district in Jammu and Kashmir recently experienced severe weather, including heavy rainfall and hailstorms, leading to significant destruction in the area.

According to the India Meteorological Department (IMD), the region recorded 16.9 mm of rainfall within a 24-hour period—an astonishing 575% increase compared to the average of 2.5 mm typically expected for this time.

Understanding Cloudbursts

A cloudburst is an intense, highly localized rainfall event characterized by extreme precipitation in a short span. It generally involves more than 10 cm of rain falling within an hour over an area of about 10 km × 10 km. Even 5 cm of rainfall in just 30 minutes over the same area can also be categorized as a cloudburst.

These events occur more frequently in mountainous regions due to a phenomenon known as orographic lift. This happens when:

• Warm, moist air is pushed upward along mountain slopes.
• As the air rises, it expands and cools, leading to condensation and heavy precipitation.
• If this moist air continues to rise without releasing its moisture gradually, it can result in an abrupt and intense downpour.

Due to their confined scale and sudden onset, cloudbursts are challenging to predict and often result in flash floods and landslides.

What Are Flash Floods?

Flash floods are sudden, rapid floods that occur when an overwhelming volume of rainwater floods streams, drains, or rivers in a short time, exceeding the capacity of natural or man-made drainage systems. These are particularly common in hilly regions where the rocky ground does not absorb water effectively, causing increased surface runoff.

Unlike seasonal river floods in plains that develop gradually, flash floods strike quickly and are often more lethal, catching people off guard and sometimes resulting in casualties.

What Causes Landslides?

Landslides involve the downward movement of soil, rock, or debris under the influence of gravity. These are often triggered when the stability of a slope is compromised—commonly due to heavy rainfall.

Rain contributes to landslides by:

• Increasing the mass of soil and rock on a slope.
• Reducing the internal cohesion and friction that keep slope materials in place.
• Allowing water to seep into the ground, loosening soil and making slopes unstable.

Landslides can have devastating consequences, including:

• Burying people and structures under debris.
• Interrupting transportation routes.
• Blocking river flow, which may cause secondary flooding.