Why in the news?

• A new study by IIT Indore, ICIMOD (Nepal), and U.S. researchers has found that the Gangotri Glacier system has lost about 10% of its snowmelt flow in the last four decades (1980–2020).

Gangotri Glacier

• Location:
  • Situated in Uttarakhand, within Gangotri National Park.
  • Lies in the Greater Himalayan ranges (Central Himalaya).
• Features:
  • Fed by snowmelt, glacier melt, rainfall, and base flow.
  • Contributes ~25% of Ganga’s water in non-monsoon months.
• Fact:
  • Largest glacier in the Garhwal Himalayas; source of the Bhagirathi River, the headstream of the Ganga.
  • Considered sacred in Hinduism, with its snout at Gaumukh cave revered as the origin of the Ganga.
• Climate Change:
  • Decline in snowmelt contribution: from 73% (1980–90) → 63% (2010–20).
  • Temperature rise: +0.5°C (2001–20 vs. 1980–2000).
  • Peak flow shift: from August → July due to earlier melting.
  • Snout retreat: steady shrinkage; aligns with Himalayan trend of ~46 cm annual ice thickness loss.
• Strategic Importance:
  • Water Security: Lifeline for millions in the Ganga basin.
  • Hydropower: Seasonal discharge changes affect generation capacity.
  • Agriculture: Altered flow timing may cause irrigation stress.
  • Cultural Significance: Sacred origin of Ganga, central to Hindu faith & pilgrimages (Char Dham Yatra).