Temporal variation in glacier surface area and glacial lakes in glaciated river basins of Arunachal Pradesh

Abstract

Climate change-induced glacier recession has sparked a dynamic transformation of glaciers in high-mountain areas worldwide, resulting in genesis, expansion, and dissipation of glacial lakes that pose a potential threat to downstream communities, underscoring the need for regular monitoring. This study incorporates the automated glacier extraction index to improve debris-free glacier mapping accuracy by reducing water and shadow area categorization errors using multi-temporal Landsat-5 Thermal Mapper, Landsat-8 Operational Land Imager, and digital elevation model (Shuttle Radar Topography Mission) to obtain precise glacier extent. Waterbodies were delineated using thresholding techniques applied to water indices: normalized difference water index, modified normalized difference water index, normalized difference turbidity index, and slope information. The study attempted to map and analyze the temporal variations of glaciers and glacier lakes in the glaciated sub-basins of Arunachal Pradesh: Dibang Basin, Mago Basin, and Subansiri Basin. Glaciers receded at a shrinkage rate of 1.08% per year (1988–2017) in Mago Basin, 1.01% per year (2013–2022) in Subansiri Basin, and 1.42% per year (1995–2021) in Dibang Basin. Glacier lakes showed an increasing trend in number and area due to glacier melt, expanding at rates of 3.31% in the Mago Basin, 0.48% in the Subansiri Basin, and 0.68% in the Dibang Basin per year. Findings suggest that global climate change is likely the primary factor driving glacier changes in these basins. HIGHLIGHTS Studied temporal variations of glacier surface area and glacier lakes associated with selected glaciated basins of Eastern Himalaya, namely Mago Basin (1988–2017), Subansiri Basin (2013–2022), and Dibang Basin (1995–2021).; The study observed and discussed the glacier dynamics of unexplored basins in Eastern Himalayan, which exhibit distinct characteristics compared to the extensively studied Western Himalayan Basins.;

Keywords

• automated glacier extraction index (agei)
• modified normalized difference water index (mndwi)
• normalized difference turbidity index (ndti)
• normalized difference water index (ndwi)