‘Millions’ in India, Pakistan at risk of flooding from glacial lakes : What a new study says ?
Context- Around 15 million people across the world face the risk of sudden and deadly flooding from glacial lakes, which are expanding and rising in numbers due to global warming, according to a new study. More than half of those who could be impacted live in four countries: India, Pakistan, Peru and China.
Published in the journal Nature, the study, ‘Glacial lake outburst floods threaten millions globally’ has been conducted by Caroline Taylor, Rachel Carr and Stuart Dunning of Newcastle University (UK), Tom Robinson of the University of Canterbury (New Zealand), and Matthew Westoby of Northumbria University (UK).
What are the findings of the new study?
- In order to identify the areas and communities that are most in danger from GLOFs, the researchers used existing satellite-derived data on different locations and sizes of glacial lakes with a global population model and a series of population metrics.
- Moreover, the researchers also looked at levels of human development and corruption in these zones to determine how vulnerable local communities may be when floods occur.
- As mentioned before, the paper estimates that 15 million people live within the 50 km danger zone of glacial lakes. It adds that populations in High Mountains Asia (HMA) — a region stretching from the Hindu Kush all the way to the eastern Himalayas — are the most exposed and on average live closest to glacial lakes with around one million people living within 10 km of a glacial lake.
- “India and Pakistan make up one-third of the total number of people globally exposed to GLOFs — around three million people in India and around two million people in Pakistan,” Robinson said.
- Another interesting finding of the study is that the glacial flood risks don’t only depend on the size and number of glacial lakes in an area. What also matters is the number of people living in the area, their proximity to the danger zone as well as the levels of social vulnerability.
- For instance, areas like Greenland and Canada, which have a large number of glacial lakes, have very few people who are vulnerable to GLOFs as their population and corruption levels are low.
- However, the most surprising bit for the scientists was to find Peru ranking third globally in danger levels. They point out that in the past two decades, due to climate change, glacial lakes across the Andes have increased by 93 per cent, in comparison to 37 per cent in high-mountain Asia.
What exactly are glacial lake outburst floods or GLOFs?
- Glacial lakes are large bodies of water that sit in front of, on top of, or beneath a melting glacier. As they grow larger in size, they become more dangerous because glacial lakes are mostly dammed by unstable ice or sediment composed of loose rock and debris.
- In case the boundary around them breaks, huge amounts of water rush down the side of the mountains, which could cause flooding in the downstream areas. This is called glacial lake outburst floods or GLOF.
- In 2013, one such event took place in Uttarakhand’s Kedarnath when the region witnessed flash floods along with a GLOF caused by the Chorabari Tal glacial lake, killing thousands of people.
How can GLOFs be prevented?
- According to Robinson, reducing the risk of GLOFs is complex and no single solution would work.
- “Limiting climate change and keeping warming under 1.5 degree Celsius is a big one as this will help slow the growth of glacial lakes, but unfortunately a certain amount of ice loss is already ‘locked in’ – if we stopped all emissions today GLOF hazard will continue to increase for several decades,” he added.
Way Forward- There is a need to find effective measures by working with national and regional governments, as well as communities themselves. This includes working at the local level and finding appropriate measures for the threatened populations.
Source- Indian Express
NEWS- ‘Millions’ in India, Pakistan at risk of flooding from glacial lakes : What a new study says ?
Syllabus- GS-1; Physical Geography
