Experts have called for a detailed mapping of geo-hazards and assessment of risks from Gorkha Earthquake that struck the country last year to identify and implement mitigation and adaptation measures.

The findings of a new study on the ‘Impact of Nepal’s 2015 Gorkha Earthquake-Induced Geohazards’ prepared by a team of national and international researchers, published by the International Centre for the Integrated Mountain Development (Icimod), has highlighted the need of a better understanding of science related with disasters and their impacts on lives and livelihoods. 

The main geo-hazard induced by the Gorkha Earthquake and its aftershocks were landslides, river channel constriction and damming, and avalanches with debris flow and air-burst. The quakes triggered more than 4,300 landslides and large avalanches. Similarly, of the total 489 glacial lakes surveyed by the two groups using satellite images, only nine showed any evidence of effects caused by the quake. 

The report has said that the earthquake and associated aftershocks resulted in considerable loss of life, especially in some remote Himalayan valleys, but the damage due to landslides and glacier lake outburst floods was less than anticipated.  

“The number of landslides was large, but much less than that induced elsewhere by other earthquakes of similar magnitude,” read the report. 

The landslides occurred mainly on steep slopes, in areas with strong shaking, near ridge crests, and in the tectonically down dropped blocks and were widespread in the earthquake-affected districts with a greater number in Dhading, Gorkha, Rasuwa, and Sindhupalchok. 

Icimod, in collaboration with other experts, undertook several studies including field surveys, airborne observations, and remote sensing mapping to assess the occurrence and impact of the geo-hazard induced by the earthquake and its aftershocks. “Damage from earthquake-induced geo-hazards can be considerable, and there is the need to treat geo-hazards separately since their nature and effects and mitigation and adaptation options are different,” said David Molden, director general of Icimod.  He said that the findings and the recommendations provided in the study will help policy and decision makers in Nepal and other regional member countries in their efforts to prepare for 

geo-hazard.