On October 4, a tragedy unfolded in Northeast India’s Sikkim state when heavy rainfall caused Lhonak Lake to overflow. This disaster is the most severe the region has witnessed in over half a century, resulting in the loss of at least 18 lives and leaving nearly 100 individuals missing.
The catastrophe is closely linked to the significant increase in rainfall attributed to climate change in the South Asian mountainous region. In just the initial five days of October, Sikkim experienced an extraordinary 101 mm (approximately 4 inches) of rainfall, double the usual amount. Lhonak Lake in Sikkim state breached its banks on Wednesday, leading to the displacement of around 22,000 people due to extensive flooding.
Weather experts are forecasting further heavy rainfall in parts of Sikkim and nearby regions over the next three days, exacerbating the already dire situation.
Scientists and government officials were in the process of creating an early warning system for floods caused by melting glaciers at a Himalayan lake in northeastern India. Unfortunately, the lake overflowed before.
The initial part of the warning system, consisting of a camera to monitor Lhonak Lake’s water level and weather equipment, had been installed just last month. If it had been fully operational, this system could have given residents more time to evacuate. Typically, glacial early warning systems can provide a few minutes to an hour of notice before a disaster.
The details of the warning system for Lhonak Lake were not previously reported. The plan included adding a tripwire sensor that would activate if the lake was on the verge of bursting. This sensor would trigger an alert system or siren to warn people to move to higher ground. However, the Indian government had not yet approved this step for this year, so it was a two-step process.
Unfortunately, the monitoring devices meant to send data to authorities encountered a problem when the camera lost power in late September for an unknown reason, according to sources at the Swiss embassy, which supported the project.
As climate change causes high mountain regions to warm up, many communities face the threat of glacial lake outburst floods (GLOFs). Research from 2022 indicates that over 200 such lakes pose a very high hazard to communities in the Himalayan region, including India, Pakistan, China, Nepal, and Bhutan. In recent years, glacial flood early warning systems have been deployed in Nepal, Pakistan, and Bhutan.
