Context

• A devastating cloudburst in Uttarkashi’s Dharali region triggered flash floods and landslides, killing at least four people and sweeping away homes.

About the News

• At least four people died as flash floods and mudslides struck Dharali village in Uttarkashi, Uttarakhand, damaging several buildings, shops, and hotels. 
• While cloudbursts are common triggers of flash floods in Uttarakhand’s hilly regions, the recent incident was not due to a technical cloudburst but rather sustained heavy rainfall over the past three days.

Factors Behind Uttrakashi Flash Floods

• Continuous rainfall over the past few days, combined with Uttarkashi’s fragile topography, triggered mudslides, debris flows, and flash floods. 
• Climate change-induced intense rainfall and accelerated glacier melting further worsened the situation. 
• Rainfall of any intensity, if continuous, recorded over such high altitudes where Uttarkashi is located, can be disastrous. 
• That is because this region is built on layers of mudslides over the past several centuries.
• Uttarkashi district is situated along the southern Himalayan slope, where there is limited vegetation and no significant obstruction.
• Link to Climate Change: Global warming increases atmospheric moisture-holding capacity. This leads to more intense, erratic, and sudden rainfall, making cloudbursts more frequent and severe.

About Cloudburst

• A cloudburst is defined by the India Meteorological Department (IMD) as rainfall exceeding 100 mm/hour over a small area (20–30 sq km).
• These events are often associated with cumulonimbus clouds in mountainous regions, caused by orographic lift and convection Currents that rapidly accumulate moisture before collapsing violently.

How Cloudbursts Happen

• Orographic Lift: In hilly regions, warm air currents push moisture-laden clouds upward. This upward movement (orographic lift) is a key reason cloudbursts are more frequent in mountainous terrain.
• Growth of Droplets: As clouds rise higher, water droplets grow larger and more form. Lightning within these clouds often delays rainfall, increasing moisture load. 
• Sudden Downpour: When clouds can no longer hold the excess moisture, they burst, releasing intense rainfall over a small area.

Hilly Reasons are more Prone

• Due to Topography, steep slopes accelerate water runoff and debris flow.
• Moist monsoon air is rapidly lifted over hills, intensifying precipitation due to Orographic Lifting.
• Rocky Terrain causes poor water absorption and rapid accumulation on the surface.

Impact of Cloudburst

• Flash Flood: A flash flood happens quickly, when a lot of rain suddenly enters into the drainage systems (waterbodies, drains), and water overflows.
• Flash floods are more common in hills, because rocky terrain does not absorb water very well.
• Example: The 2013 Kedarnath Disaster involved a cloudburst followed by massive flash floods.
• Landslide: Landslides are a geological phenomenon that involves the sudden and rapid movement of a mass of rock, soil, or debris down a slope under the influence of gravity.
• Loss of Life and Livelihood: Sudden nature of cloudbursts leaves little time for evacuation. Destruction of homes, agricultural fields, and livestock affects livelihoods, especially in rural and tribal communities.
• Damage to Infrastructure: Roads, bridges, power lines, and communication networks are often washed away.
• Social Impact: Frequent disasters create trauma, displacement, and migration pressures. Affects education, healthcare, and access to essential services in remote regions.

Why Prediction is Difficult

• Cloudbursts occur in limited areas (10–30 sq km), making them hard to detect with standard radar systems.
• The event lasts under an hour, offering little time for forecasting and issuing effective alerts.
• Installing advanced radar and AI-based forecasting models in remote areas remains expensive and underfunded.

Measures Taken In India

• The Disaster Management Act, of 2005 provides a comprehensive legal and institutional framework for the management of various disasters in India.
• The National Institute of Disaster Management (NIDM) has been providing capacity building and other support to various national and state-level disaster management authorities.
• Early Warning system: 
  • India Meteorological Department (IMD), implements the Ensemble Prediction System (EPS), which uses multiple models to improve the accuracy of rainfall predictions.
  • Doppler Weather Radars (DWRs): Installed in hilly and vulnerable regions to detect intense rainfall events in real-time.
  • Flash Flood Guidance System (FFGS): Developed with WMO support to provide early warning for flash floods across South Asia, including India.
• Mobile-based Alert Systems: IMD and NDMA use SMS and app-based alerts to inform people in real-time.

Way Ahead

• To effectively mitigate the impact of cloudbursts, India must adopt a comprehensive and proactive approach that combines scientific forecasting, infrastructural resilience, and community-based preparedness.
• Land use planning and zoning regulations must be strictly enforced to prevent construction in high-risk zones. 
• Urban and rural infrastructure should be designed to handle sudden surges in water flow, with emphasis on stormwater drainage systems, slope stabilization, and rainwater harvesting.
• Also there is a need to integrate climate change adaptation into disaster management planning as intensity of such extreme weather events has increased.