Mitigation Strategies for Glacial Lake Outburst Floods

Hazard mitigation tactics aim to reduce the likelihood of a glacial lake outburst flood (GLOF) occurring and/or the potential severity of a GLOF in order to reduce the risk of GLOFs. This can be done, for instance, by lowering the volume and water level of glacial lakes or by strengthening and stabilising their dams.

• In the wake of the recent disaster in Chamoli, the National Disaster Management Authority (NDMA) released guidelines on how to deal with disasters caused by glacial lake outburst floods. Risk reduction starts with the identification and mapping of glacial lakes, the development of structural measures to prevent their breach, and the development of robust tools to preserve property and life in case of a breach.
• Field observations, historical events, geotechnical and geomorphologic aspects of the lake/dam and its environs, and identifying other physical variables are used to make the identification.
• According to NDMA, synthetic aperture radar imagery can be used to detect changes to water bodies during the monsoon season in addition to detecting lake formations. Remote lake monitoring from space is also suggested.
• The NDMA recommends using techniques such as controlled breaching, pumping out water, and digging tunnels through the moraine barrier or under ice dams to decrease lake volume structurally.
• The guidelines also recommend restricting construction in the areas prone to glacial lake outburst floods -as an easy, low-cost manner to mitigate the disastrous impact of such events.
• Besides that, the group suggests relocating existing infrastructure and habitations from high-hazard areas.
• There should be proper land use planning for the areas prone to glacial lake outburst floods.
• In case of a catastrophic event, local people are the first responders before trained rescue personnel arrive, so training them for search and rescue operations is a crucial item.

The goal of GLOF vulnerability reduction is to lessen and mitigate the consequences of GLOFs. This can be accomplished, for instance, through knowledge creation, information sharing, building of capacity, cultivation of economic diversity through good governance, various preparedness and disaster relief programmes, insurances, and loss compensation.