Uncertainty Over Cause of Uttarkashi Flash Flood

• Uncertainty surrounds the cause of a flash flood and debris avalanche in Uttarkashi, Uttarakhand, following heavy rain.

• Rescue and relief operations have delayed scientific investigations into the disaster’s cause.

• Rainfall data from the India Meteorological Department suggests that the disaster was not a cloudburst, but a glacier lake overflow or heavy rain triggering a landslide.

• Confirming cloudbursts requires specific instruments like a doppler weather radar (DWR) and an automatic weather station (AWS).

• The IMD only indicates eight-hour or 24-hour rainfall data, leaving vast stretches of the Upper Himalayas unmapped.

• Satellite imagery and other remote sensing could provide some answers, and the National Disaster Management Agency is coordinating an investigation.

• Climate change is intensifying monsoon extremes in the Himalayas, causing flash floods and landslides.