New Delhi: One in four hydropower project sites along the Himalayan Rivers are likely to face severe damage from earthquake-triggered landslides, according to a research.

The research published in Geophysical Research Letters was conducted by researchers from the Institute of Earth and Environmental Science, University of Potsdam, Germany, who compiled damages to 41 hydropower projects after Nepal’s 2015 earthquake, and used that data to estimate earthquake-triggered damages to projects in other parts of Himalayas.

According to the study, nearly one fourth of existing, currently constructed and planned hydropower projects along Himalayan rivers have high probabilities of moderate to severe damage during future earthquake.

The model developed by the research team, which took into account the combined effect of ground shaking and river steepness, was applied to projects in Indian, Nepalese and Bhutanese Himalayas. The findings also indicate that more than 10% of potential hydropower project sites in Himalayas could be unsuitable for hydropower infrastructure.

“Our study points to an urgent need to re-evaluate hydropower development in the Himalayas," according to geologist Wolfgang Schwanghart. The model would also help in making a more accurate assessment of risks at locations for potential hydropower plants.

The research is significant since Himalayas are global hotspots for harnessing hydropower energy and most of the potential hydropower project sites are along Himalayan Rivers. But it is also the world’s most active regions seismically .

Nepal lost at least 20% of its hydropower capacity in the 2015 earthquake, which killed nearly 9,000 people and damaged more than 31 hydropower projects.

Schwanghart and his team found that it was not the ground shaking that damaged most of these projects. Landslides triggered by the quake caused maximum losses.

“They survived the quake, but got wiped out by moving debris." said Schwanghart, highlighting that sites located along steep rivers with towering sidewalls were prone to becoming unstable during strong seismic ground shaking.

The study called for an urgent need to assess the vulnerability of hydropower infrastructure to the risk of nature’s extreme events.