Glacier Lake Changes in Uttarakhand, India from 2013 to 2023 using High Resolution Satellite Images

ABSTRACT The enhanced climate warming from the early 20th century caused large-scale glacier retreats and mass losses, which induced the formation of new glacier lakes and increased the extension of many existing glacier lakes. This study deals with the glacier lake changes in Uttarakhand from 2013 to 2023 using high-resolution Resourcesat LISS IV images. In this decade, the number of glacier lakes increased by 1.9%, while the area covered by them increased by 8.1%. This rise is mainly attributed to rising temperatures in the region over the last some decades. The number of glacier erosion lakes and moraine-dammed lakes increased, while the area of supraglacial lakes decreased. The glacier lakes were distributed between 2900 m - 6100 m asl, and 1001 lakes out of 1290 occur above 4500 m asl. The Alaknanda basin has the maximum number and area of glacier lakes (580), followed by the Bhagirathi basin (341). In contrast, no glacier lakes were found in the Ramganga basin. The total area of glacier lakes increased in all the ten river basins. However, in the Alaknanda basin, the number of glacier lakes decreased by 8.6%, while the Dhauliganga and Pinder basins showed negligible changes in lake numbers. Elevation-specific changes revealed an expansion in lake areas above 4000 m asl, whereas a decline in lake numbers was observed between 3500 and 4500 m asl. Out of the 13 administrative districts in Uttarakhand, glacier lakes are distributed only in six districts, which corresponds to the presence of glaciers at high altitudes. A maximum number and area of glacier lakes were found in the Chamoli district, followed by Uttarkashi. Our study recommends field surveys and further investigations using high-resolution satellite data to understand the potential hazards posed by these lakes to infrastructure and human lives.