Gangotri Glacier Retreat: indicating changes in meltwater patterns because of climate change

What is it?

The Gangotri Glacier System (GGS) is an important origin of the Bhagirathi River, a significant tributary of the Ganga.

Includes Gangotri, Chaturangi, Raktavaran, and Meru glaciers; approximately 549 km² area, around 48% glaciated.

Trends:

Average yearly discharge (1980–2020): 28 ±1.9 m³/s.

Sources of contribution: Snowmelt (64%), Glacier melt (21%), Rainfall-runoff (11%), Base flow (4%).

Peak discharge shift: From August (pre-1990) to July (post-1990) as a result of decreased winter snowfall and earlier summer thawing.

Decrease in snow cover: Lower snowmelt even with increasing temperatures.

Rainfall-runoff and baseflow rising, indicating hydrological shifts due to warming.

Consequences:

Increased peak discharge → potential for water shortages in late summer/autumn for downstream areas.

Increased flood risk in July due to heavy monsoon downpours.