The April 25 earthquake last year triggered more than 4,000 landslides of different nature, and communities living in Gorkha, Nuwakot, Rasuwa, Sindupalchok and Rasuwa, the districts located along the northern part of Kathmandu Valley, are at high risk, according to experts.

The landslides triggered by the quake last year were of different nature including shallow landslides and dry debris fall, rock fall and debris flow and mud flow among others, mainly originating at a high crest or a peak, concentrating along the main shock area stretching from Barpak in Gorkha to Singati in Dolakha.

“The villagers living along the various watersheds and slopes located in the districts worst-hit by the earthquake are most vulnerable from rock slide and debris flow movement when it starts to rain during monsoon,” said Ranjan Kumar Dahal, associate professor, Geodisaster Research Centre at Tribhuvan University.

Dahal was among one of the dozens of experts who presented their papers in the two-day International Workshop on Gorkha Earthquake that concluded on Monday. The field observations from his study on earthquake-induced landslides in Nepal after Gorkha earthquake and Sikkim-Nepal border earthquake

The investigation of coseismic landslides and associated newmark displacements in the Bhote Koshi Watershed of Central Nepal by Gorkha Earthquake led by Megh Raj Dhital, professor at the Central Department of Geology found around 2,000 landslides in central Nepal. The study further revealed that the distribution of slides is strongly controlled by their position on the landscape as many slides were found to be originating at a high crest or a peak due to high ground vibrations at the top of slope and along the crests than those at their respective bases.

The field investigation of landslides was carried out in different locations in Gorkha, Dhading, Rasuwa, Sindhupalchok, Dolakha and Ramechhap.

“From our study we found that around 15 percent of the landslides induced by the Gorkha Earthquake pose

significant threat to livelihoods and infrastructure in some worst-hit districts

during monsoon,” Dhital said, adding, “There are couple of villages including Laprak in Gorkha that need complete relocation due to the landslide threat,”.