NEW DELHI: More than one cloudburst in Uttarakhand’s Uttarkashi district on Tuesday triggered flash floods and caused large-scale damage in high-altitude villages such as Dharali and Sukhi Top. The incident is the latest in a series of extreme weather events to hit the region during the monsoon season. Here’s a breakdown of what a cloudburst is and why regions like Uttarakhand are at high risk.According to the India Meteorological Department (IMD), a cloudburst is defined as rainfall exceeding 100 millimetres per hour accompanied by strong winds and lightning, occurring over an area of 20 to 30 square kilometres.However, a 2023 research paper by scientists from the Indian Institute of Technology (IIT) Jammu and the National Institute of Hydrology, Roorkee, published in the International Handbook of Disaster Research, defines a cloudburst as a “sudden downpour of rainfall in a range of 100-250 millimetres an hour in a short span covering a smaller spatial extent similar to one square kilometre”.The Indian Himalayan region is considered particularly prone to extreme weather, including cloudbursts, flash floods, avalanches, and heavy precipitation. These risks are projected to increase with climate change.Such events typically occur during the monsoon and can lead to damage to infrastructure and disruption of daily life. “This results in widespread damage to property and lives, and potential flash floods and landslides. Houses collapse, traffic is disrupted and human casualties occur on a large scale,” the 2023 paper notes.The document further highlights that cloudbursts frequently occur in areas located at altitudes between 1,000 and 2,000 metres. These include densely populated valleys of the Himalayan range. Uttarkashi, the site of the latest cloudburst, is situated at approximately 1,160 metres above sea level.It also states that cloudburst events per unit area are “very high in Uttarakhand” compared to other regions in the Indian Himalayas, and recent events have had more severe impacts on local communities.In previous incidents, Uttarakhand has seen similar extreme rainfall events. On July 26, heavy rain in Rudraprayag district triggered a landslide that blocked the trekking route to Kedarnath. Authorities evacuated over 1,600 pilgrims travelling as part of the Chardham yatra.On June 29, a sudden cloudburst at Silai Band on the Barkot-Yamunotri Marg led to damage at an under-construction hotel site, with eight to nine workers reported missing.Experts argue for a stronger policy response and better planning mechanisms to address the growing frequency and impact of such disasters. “Researchers call for concrete policies, planning and management of cloudburst events by national and global organisations,” the paper concludes.(With inputs from news agency PTI)