In Ladakh, a glacial lake outburst flood hit the village of Gya in August 2004. The flood destroyed houses, fields and bridges. Researchers from Germany have used remote sensing data and mapped the evolution of Gya glacial lake and tried to find the cause of this flood.
These researchers recently published their paper in Natural Hazards which says that this case study depicts the problem of potentially hazardous lakes not getting attention.
The research found that the flood was not caused by spillover but rather a tunneling drainage process. Ravi Baghel from the South Asia Institute, Geography department, Heidelberg University explains that consider a bucket full of water. If you drop a stone in it, then it will overflow and if you make a hole in it then the water will drain. The flood did not take place because of any spillover due to any landslide or avalanche, in place there was a thawing of the ice cores in the moraine.
The research paper pointed out that the thawing of ice cores may increase in the future as an effect of global climate change. We should urgently shift to use many methods for an early warning and better risk assessment.
Marcus Nusser, lead author of the paper wrote in an email that there are high chances that other glacial lake outburst floods will take place all over the Himalayas. However, it is expected that all of these events will not have any catastrophic results.
It depends on aspects like urban planning, the distance between the lake, the size of the lake, and affected villages, the valley section. As happened in 2013, in some cases cloudbursts can also trigger glacial lake flood outbursts like happened in Kedarnath. He added that the occurrence of flood has received different attention in various parts of the Himalayas.
Dr Nusser wrote that these events have been regarded as a major risk in the Central Himalayan region including Sikkim. Glaciers are located at high altitudes in Ladakh and most of them are of smaller sizes. The glacial lakes are also very small in size. Gya lake is almost ice-covered, even during the summer.