Monitoring the moraine lakes in Nepal
In Nepal, at least twenty glacial lakes pose a significant danger to villages downstream. Moraine dams can collapse under the weight of the water and cause catastrophic floods, threatening local populations, hikers and mountaineers. The Petzl Foundation is now supporting a geotechnical study to find affordable solutions.
SEPTEMBER 2014
The Thulagi lake is 4,040 meters high.
- Project partner: Des géorisques et des hommes (geohazards and men) association
- Country: Nepal, Asia
- Project type: Gaining knowledge
- Budget: €45,000 from 2012 to 2014
Accelerated glacial melting due to global warming is one of the root causes of the formation of an increasing number of glacial lakes. Meltwater and rain are trapped by old frontal and lateral moraines that act as natural dams, some of which are not able to withstand the water pressure and burst. Rupture of a moraine dam usually results in the rapid draining of the lake which in turn causes catastrophic floods.
The association "Des géorisques et des hommes"
The Thulagi lake is 4,040 meters high. It measures 2.4 km in length and is about 400 meters wide. It has already ruptured twice. The 2013 survey of this lake confirmed the current strength of the moraine dam.
The Lumding lake dam, nestled at an altitude of 5,000 meters, appears strong because of its width and the presence of shallow bedrock. The researchers focused on one of two smaller lakes upstream, where the dam presents a greater risk. Its discharge into the main lake could potentially submerge the Lumding lake dam.
This mission also allowed the team to study two more lakes: Chola and Dudh Khunda, which also have a high risk of rupture, even if they are not currently on the danger list.
Photos : association GDH.