Arunachal Pradesh is witnessing accelerated glacier melt in the Eastern Himalayas, sparking concerns about potential glacial lake outburst floods (GLOFs) and long-term water security in the region. Recent studies have highlighted a significant retreat in glacier mass over the past three decades, with experts attributing this to rising global temperatures, erratic precipitation patterns, and environmental disturbances.
Researchers from Nagaland University and Cotton University have documented a concerning average glacier loss of 16.94 square kilometers per year in Arunachal Pradesh between 1988 and 2020. In 1988, 756 glaciers covered approximately 585.23 square kilometers. However, by 2020, the number of glaciers had decreased to 646, with the total area reduced to 275.38 square kilometers. Smaller glaciers, those less than 5 square kilometers, are reportedly retreating at a faster rate.
The rapid melting has led to the formation and expansion of glacial lakes, increasing the risk of GLOFs. These events occur when glaciers melt rapidly due to climate change, causing a sudden discharge of water downstream. A particularly vulnerable site is Rani Lake in Tawang, where scientists have measured 1.5 meters of ice melt using vertical stakes. This accelerated melting can destabilize the lake, potentially leading to catastrophic flooding in downstream settlements.
The consequences of glacier retreat extend beyond immediate flooding risks. Communities that rely on glacial meltwater for agriculture and drinking water may face water shortages in the future. Initially, melting glaciers can cause flooding and unstable river flows, but over time, the reduced glacial mass will result in decreased water availability. This poses a severe threat to water security, biodiversity, and the livelihoods of indigenous communities.
In response to these growing threats, the National Disaster Management Authority (NDMA) has dispatched expert teams to assess the GLOF risk in six high-risk glacial lakes across Arunachal Pradesh. These teams will focus on lakes in the Tawang and Dibang Valley regions, part of a larger effort to study 27 high-risk lakes identified across five districts in the state. This action follows a devastating GLOF event in South Lhonak Lake, Sikkim, in October of the previous year, which swept away a major hydropower project and caused significant casualties.
Scientists and officials emphasize the urgent need for long-term monitoring systems, satellite-based alerts, and real-time early warning mechanisms to protect vulnerable communities. They also advocate for disaster preparedness plans at regional and national levels, recognizing that glacial changes are a global climate crisis with implications for regions far beyond the Himalayas. Experts are calling for sustainable development policies, including afforestation, community-led conservation programs, and strict regulations on deforestation and industrial activities in ecologically fragile zones.
