Geologists and experts have said that multiple natural calamities backed by global warming caused the recent Melamchi River catastrophe in Sindhupalchowk.

The disaster wreaked havoc on multiple settlements, destroyed hundreds of houses and killed more than 30 people. It has also displaced thousands of people and put the future of the valley's most anticipated drinking water project in doubt.

The reason behind the havoc this monsoon was caused largely due to heavy rainfall followed by landslides.

"The heavy rainfall was likely caused by global warming," said Shiva Baskota, senior meteorologist of NDRRMA. "Before the June 14 -15 flooding, the temperature in the high altitude Himalayas, from where the two major rivers originates, used to range between minus 10 and minus 15 degrees Celsius. But, during monsoon, the temperature had risen to plus five degrees Celsius."

Baskota said. He added that the very phenomenon triggered very rare rainfall which occurred above the snowline. "We all know rainfall normally does not occur in the Himalayas, but global warming has changed the story now,"

Baskota said. "We also saw afterwards that the mountains in the Himalayas of the area were stripped of thick snow," he added.

Experts have said that the two major landslides at the Bhemathang ground around 30 kilometres uphill from Melamchi Bazar and another landslide at the origin spot at Pemdam River caused massive flooding in the area along the Melamchi river.

Bhemathang area is a junction of Melamchi and Pemdam rivers. Earlier, there used to be a small flat land in the area. Following the flooding, the area has been left with up to 15 metres thick rubble spread in an area of over 1,780 metres by 500 metres. Likewise, another landslide occurred at the Pemdam River origin point near the Himalayan range.

Speaking at a report launching a programme by National Disaster Risk Reduction and Management Authority about the Melamchi calamity, experts further warned that similar calamities could happen any time.

The rubble, which has also spread over low settlements of Melamchi bazar has covered the city with thick mud.

There are up to four-storey tall buildings in the town area. Experts in the programme said the rubble was so massive in the area from Melamchi bazaar to the top of Melamchi River that around six million trucks would be needed to remove it if done manually.

Similar comments were made by Arun Bhakta Shrestha, Engineer at International Centre for Integrated Mountain Development during an interaction organised by Nepal Forum of Environmental Journalists. He said unstable sedimentation in the area had rendered the area more vulnerable, adding that the temperature in high altitude areas had increased significantly due to global warming.

Head of Environment, Science and Engineering Department of Kathmandu University Rijan Bhakta Kayastha said it was crucial to remain alert as any smaller or bigger river basin in the area might cause similar havoc with comparatively lighter rainfall any time soon.

A version of this article appears in the print on August 16 2021, of The Himalayan Times.