Spatio-temporal variations of geo-climatic environment in a high-altitude landscape of Central Himalaya: An assessment from the perspective of vulnerability of glacial lakes

Abstract

Impacts of climate change on snow cover, permafrost and glaciers at varied elevations are wide-ranging and well-known. Melting water from glaciers forms glacial lakes; where, under the changing climate and accelerating glacial retreats have been a prime cause of glacial lake growth and outbursts. Indian Himalayan Region has also witnessed those impacts on glacial lakes with several evidences of glacial lake outbursts in recent years affecting people and ecosystems. Thus, to provide an understanding of geoclimatic environment and glacial lakes of the region, this article has attempted to look into the spatio-temporal changes of climatic conditions and physical landscape in Chamoli district of Uttarakhand in Indian Himalayan Region. In this study, mapping of glacial lakes in the district has been done to look into the aspects of associated hazards. The assessment has been done using historical trend analysis of climatic parameters, land surface temperature (LST) and physical landscape change in the study area. Seismic activities of the region have also been taken into account to understand the vulnerability of glacial lakes. The results indicate dynamic environmental conditions with visible physical landscape change; where, an increase in built-up area by 541.57 ​km2, a decrease in dense forest and fallow land by 76.96 ​km2 and 364.09 ​km2 respectively over a period of two decades (2000–2020) have been observed. Minimum temperature has been gradually increasing by 0.68 ​°C per decade. The geospatial analysis provides identification of ∼500 glacial lakes, where 40.92% are situated at 5000–6000 ​m elevation. It is understood that glacial lakes of the study area are prone to produce disasters in the region because of changing climate and active seismicity, and lakes at higher elevation are highly susceptible to GLOF (Glacial Lakes Outburst Flood). Moreover, prevalence of large number of supraglacial lakes in the study region which are dynamic in nature, makes the area more vulnerable to hazards. The very old supraglacial lakes in high altitude region need attention and detailed study in terms of their changing characteristics and stability. Anthropogenic interventions in the area are contributing towards higher intensity of impacts on human and resources. It is suggestive that further development activities should consider the potential hazards and vulnerable zones in Himalaya. The disaster risk reduction strategies should prioritize development of early warning systems in the region.

Keywords

• GLOFs
• Indian Himalayan region
• Climate change
• High altitude lakes