A new study by IIT Indore, ICIMOD, and US researchers finds that the Gangotri Glacier System has lost 10% of its snowmelt flow (1980–2020) due to rising temperatures, shifting peak flows, and changing hydrological composition.

Key Findings of the Study

1. Snowmelt Decline
   • Gangotri Glacier System lost ~10% snowmelt flow (1980–2020).
   • Snowmelt share declined from 73% (1980–90)  to 52% (2000–10) and  partial recovery 63% (2010–20).
2. Changing Flow Composition
   • Long-term (1980–2020 average):
     • Snowmelt  64%, Glacier melt – 21%, Rainfall-runoff – 11%, Baseflow – 4%.
   • Increasing contribution of rainfall-runoff and baseflow due to warming.
3. Temperature Rise
   • Mean annual temperature increased by 0.5°C (2001–20 vs 1980–2000).
   • Highest decadal temperature: 3.4°C (2001–10)  also the highest discharge.
4. Shift in Peak Flow
   • Peak discharge has shifted from August to July since the 1990s.
   • Triggered by reduced winter precipitation and earlier summer melting.
5. Decadal Flow Trends
   • Maximum discharge 28.9 m³/s in 2001–10, coinciding with highest warming.
   • Snow cover area shows a decreasing trend, while rainfall-runoff shows an increasing trend.
6. Short-term Anomaly (2010–20)
   • Sudden increase in snowmelt proportion due to −2°C lower winter temperatures and +262 mm winter precipitation, causing more snow accumulation.
7. Climate Change Signature
   • Long-term decline in snowmelt + rise in rainfall-runoff and baseflow = warming-induced hydrological transformation.
   • Confirms Himalayan glaciers’ rapid thinning (≈ 46 cm annually, corroborated by other studies).

About Gangotri Glacier

• Situated in Uttarkashi district, Uttarakhand, central Himalayas.
• Part of the Greater Himalaya range.
• Source of the Bhagirathi River, a primary headstream of the Ganga.
• Raktvarn, Kirti Bamak, and Chaturangi are well-known tributary glaciers of the Gangotri glaciers system.

DOWNLOAD PDF