On October 4, 2023, a tragic event unfolded in the Himalayas, as a cloudburst above Lhonak Lake in North Sikkim triggered a Glacial Lake Outburst Flood (GLOF). This disaster claimed over 30 lives, obliterated the 1,200 MW Urja Hydroelectric Chungthang dam, and left a trail of destruction downstream. A stark reminder of the compounding and cascading risks induced by climate change, the Sikkim GLOF exemplifies the fragility of the Himalayan mountainous region and the severe threats it faces.
Unveiling GLOF and Cloudburst Dynamics in Himalayas
Glacial Lake Outburst Floods (GLOFs) stem from the sudden rupture of glacial lake dams. The Sikkim Himalayas, particularly the Teesta basin, are home to a plethora of such glacial lakes. South Lhonak Lake, one of the largest and fastest-growing glacial lakes in the region, presents an alarming illustration of this phenomenon. As rising temperatures intensify glacial melt, these lakes expand, increasing the vulnerability of downstream communities.
Cloudbursts, on the other hand, are characterized by an abrupt, intense deluge of precipitation over a small area within a short timeframe. In hilly terrains like the Himalayas, the local topography, wind systems, and temperature gradients between lower and upper atmospheres foster cloudburst occurrences. These events frequently trigger landslides and flash floods, potentially leading to catastrophic GLOFs.
The Complex Dynamics of Cascading Disasters
Cascading disasters, such as the Sikkim GLOF, pose a unique challenge. Unlike isolated events, cascading disasters entail a sequence of events that amplify each other’s impacts. A vivid example of this complexity is the triple disaster that struck Japan, where an earthquake triggered a tsunami, leading to the Fukushima nuclear crisis. Preparing for such cascading events, especially in the Himalayas, requires a different approach, given their increased frequency and intensity.
Managing Cascading Risk in the Himalayas
The management of cascading risk necessitates a holistic, integrated approach. It’s crucial to consider the interplay between various hazards, sectors, and specific incidents in developing effective risk mitigation strategies. Instead of viewing risks through a single hazard-single sector lens, a paradigm shift is essential. Embracing a multi-hazard, multi-sectoral, and systemic risk perspective is the way forward.
In the Himalayan context, where cascading risks are prevalent, a twin-track strategy for resilience can be built upon:
Track 1: Early Warning Systems for GLOFs
To effectively address the threat of GLOFs, deep understanding of risk is paramount. Existing efforts to install early warning systems, such as cameras and weather instruments, should be expanded. These systems must encompass the complex and cascading risks involved, including cloudbursts. The UN Early Warnings for all initiative offers a comprehensive approach that covers risk knowledge, warning, forecasting, risk communication, and response. GLOF early warning systems should be people-centered, risk-informed, utilize impact-based forecasting, and cater to the needs of critical sectors such as energy, water, transport, ICT, and social.
Track 2: Resilient Infrastructure and Infrastructure for Resilience
The Himalayan region requires a twofold approach to infrastructure resilience. ‘Resilient infrastructure’ should be capable of absorbing, withstanding, rebounding, and adapting to hazard events and shocks. Simultaneously, ‘infrastructure for resilience’ should contribute to broader social and economic resilience. Given the interdependence of critical infrastructure sectors and the increasing digitization of services, there is a pressing need to ensure that local emergencies do not escalate into widespread disruptions across multiple sectors. Resilient services can act as buffers against asset loss or damage, mitigate disruptions, and facilitate rapid recovery or adaptation.
In the face of compounding and cascading risks in the Himalayas, adopting a multi-faceted approach is crucial. This region, rich in natural beauty, requires innovative strategies to safeguard both its environment and the communities that call it home.