Wednesday, February 28, 2024

Research reveals dangers of glacial flooding

A new study identifying regions around the world where people are most at risk from flooding caused by melting glaciers could help save vulnerable lives, according to new University of Canterbury research.

School of Earth and Environment Senior Lecturer, Dr Thomas Robinson says glacial lake outburst floods (GLOFs) can happen without warning when a natural dam fails.

“Continued ice loss and expansion of glacial lakes due to climate change means glacial outburst floods are a globally important natural hazard that requires urgent attention to minimise future loss of life,” he says.

Dr Robinson is the corresponding author for an article published today in international journal Nature Communications that for the first time identifies the areas and communities worldwide most in danger from this growing natural hazard.

“Our research is novel because it identifies the populations who live downstream from these lakes and how vulnerable they are,” he says.

“Since 1990 the number and size of glacial lakes has grown rapidly. We show that currently 15 million people globally are exposed to impacts from potential glacial lake outburst floods.

“People in High Mountains Asia are most exposed and on average live closest to glacial lakes with about 1 million people living within 10 km of a glacial lake.”

The new research identifies that more than half of the world’s exposed population is found in just four countries: India, Pakistan, Peru, and China.

“While High Mountains Asia has the highest potential for glacial lake outburst flood impacts in India, Pakistan and China, we highlight the Andes, which affects people living in Peru and Bolivia in particular, as a region of concern with similar potential for GLOF impacts but fewer published research studies,” Dr Robinson says.

The Himalayas have been a popular subject for research, accounting for 36% of glacial outburst flooding studies carried out between 2017 and 2021. But Dr Robinson says the Andes has a similar level of danger and is far less well-studied.

“Since 1990, the number of glacial lakes in the region increased by 93% compared to 37% in High Mountains Asia, and as a nation, Peru, has the third highest danger of glacial lake outburst flooding globally.

“The big message is that if you want to understand the risk you can’t just look at the hazard, you have to think about where people are and how vulnerable they are,” Dr Robinson says.

“We can’t just focus on the Himalayas because it’s higher profile and ignore the risks faced in the Andes. We need to make sure we are looking at the big picture and the areas with large numbers of vulnerable people.”

He says some valleys contain many large glacial lakes but they have very few people living downstream so they’re comparatively less dangerous. But in parts of Pakistan, India and Peru there are huge numbers of people living in these valleys.

Those living in the Andes region are also very vulnerable to the impact of a such a disaster, according to the researchers’ measures of corruption, poverty, education levels and other factors. By contrast, New Zealand is rated the least vulnerable.

Dr Robinson says it’s important to work closely with the exposed communities identified in the study to prevent major disasters.

“We are keen to work with national and local governments in these high-risk areas to help identify and explore potential mitigation options, evacuation drills and early warning systems for flooding. It’s about working alongside them so they can minimise the risk to human lives. 

“We hope our research can be used to help protect vulnerable communities, and help local communities, governments, and international groups like the United Nations prioritise the most dangerous locations.”

The study is based on the latest published data on lake conditions, exposure and vulnerability data, and is a snapshot of the risk faced in 2020.

The research team also plans to explore how that risk has changed in the years since then, and what could potentially happen in the future.

The Nature Communications article can be read here.

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