Studies show frequency of cloudbursts increasing

The flash flooding and landslide triggered by torrential rain in Jammu and Kashmir has brought the spotlight on extreme weather events battering India’s Himalayas this monsoon season, a trend that tracks with rising extreme weather events as global temperatures have risen.

- Jayashree Nandi

The incident in J&K comes on the back of another deadly flood on August 5, when suspected glacier collapse triggered flash floods in Dharali region of Uttarakhand. Extreme monsoon rainfall and flash floods also struck Kullu, Shimla, Lahaul and Spiti this week, continuing a pattern of escalating disasters across Uttarakhand, Himachal Pradesh and Jammu and Kashmir.

Multiple peer-reviewed studies published since 2017 have documented the increasing frequency of cloudbursts and flash floods across the Western Himalayas. Experts attribute this to rising temperatures that increase the atmosphere’s water-holding capacity, leading to more intense rainfall events, compounded by unplanned construction in vulnerable areas.

The physics behind the increasing intensity are straightforward, according to Anil Kulkarni, distinguished visiting scientist at the Divecha Centre for Climate Change at the Indian Institute of Science.

“Higher temperature increases water holding capacity of the air,” Kulkarni explained. “Mountainous regions due to higher slope are associated with upward movement of air mass. As atmospheric moisture is moved upward it increases size of water droplets, in the meantime, additional moisture is added at lower altitude. This significantly increases moisture in the air column. This leads to cloudburst.”

Research data supports this mechanism. A study published in July in the Journal of Geological Society of India titled “Uttarakhand: A Hotspot for Extreme Events?” documented a marked increase in extreme events over Uttarakhand after 2010, particularly during monsoon season.