Experts from the worldwide Earth science community have come together to analyze the significant Sikkim flood, aiming to help prepare for future similar disasters.
Experts from the global Earth science community—including a scientist from the University of Calgary—have assembled to understand what transpired during the major Sikkim flood, with the goal of aiding others in getting ready for comparable calamities.
On October 3, 2023, a series of hazards in the Sikkim Himalayas, India, was set off when a permanently frozen lateral moraine—accumulated debris from glacier erosion—collapsed into South Lhonak Lake.
“A landslide fell into a lake, causing a wave that eroded a dam at the lake’s edge, resulting in a slurry-like flood extending for hundreds of kilometers,” explains Dr. Dan Shugar, PhD, an associate professor in the Department of Earth, Energy and Environment within the Faculty of Science.
This event, known as a glacial lake outburst flood, resulted in the loss of at least 55 lives, left many individuals unaccounted for, damaged farming areas, and destroyed a hydropower dam.
The World Meteorological Organization highlighted the Sikkim flood as one of the most severe climate-related catastrophes on the continent for the year, according to its State of the Climate in Asia 2023 report.
A new article in the journal Science details a collaborative study involving scientists, academics, government entities, NGOs, and others examining this disaster.
Shugar, a geomorphologist and co-author of the paper, emphasizes the significance of thoroughly analyzing the events to extract valuable lessons, especially with the rapid climate changes impacting mountainous areas worldwide.
The research paper investigates the factors and origins of the disaster while assessing its downstream effects using advanced satellite imagery, seismic and meteorological data, as well as field observations. It also examines what triggered the flood, reconstructs its hydraulic dynamics, evaluates the implications downstream, and considers the long-term consequences of the incident.
“Our assessment demonstrates that the heightened risk level stems not just from the initial flood but also from the subsequent events it sets into motion,” the paper states.
Dr. Ashim Sattar, PhD, the study’s main author and an assistant professor in the School of Earth, Ocean, and Climate Sciences at the Indian Institute of Technology, noted that the Sikkim flood had catastrophic effects on the areas downstream.
“This is the critical moment to enhance resilience in the downstream areas that are vulnerable to such potentially devastating occurrences in the Himalayas,” he remarked in a statement.
“The increasing likelihood of these catastrophic events emphasizes the urgent need for measures to safeguard both our environment and the communities in the Himalayas and comparable areas globally.”
Sattar indicated that the number and size of glacial lakes are on the rise, necessitating urgent evaluation for risks and potential harm downstream.
“Climate change is altering permafrost temperatures, raising the risk of slope failures that could result in avalanches or initiate glacial lake outburst floods in high mountain regions.”
For instance, in Canada, a glacial lake outburst flood in the southern Coast Mountains of British Columbia destroyed forests and salmon spawning areas in November 2020.
Shugar, who has researched both incidents, warns of their severe implications for people and infrastructure.
“The study on the Sikkim flood serves as an excellent example of a mountain disaster prompting the global Earth science research community to unite towards a shared objective,” he comments.
“Recent advancements in Earth observation technologies over the last ten years have greatly enhanced our comprehension of such events, ultimately contributing to disaster risk mitigation.”
