Reduction of springs in Himalayas

Why in news?

A Recent study showed that the spring system in Himalayan region, especially in Himachal Pradesh sees drop due to climate change

• Springs – It occurs when water pressure causes a natural flow of groundwater onto the earth's surface.
• Mechanism – As rainwater enters or "recharges" the aquifer, pressure is placed on the water already present.

• This pressure moves water through the cracks and tunnels within the aquifer, and this water flows out naturally to the surface at places called springs.
• Hot springs Spring with water at temperatures substantially higher than the air temperature of the surrounding region.
• Causes of heating
  • Volcanic activity – By shallow intrusion of magma
  • Convective circulation – Percolation of groundwater deep reaching hotter rocks
• Hot springs of the Himalaya – They are located in the zones of deep faults that define tectonic boundaries
  • Indus Tsangpo Suture – Between the Himalayan province and mainland Asia
  • Main Central Thrust – Between the Great Himalaya and Lesser Himalaya
  • Main Boundary Thrust – Between the Siwalik domain and the Lesser Himalaya

In the Eastern Himalayas Meghalaya has the most villages with springs, while Sikkim with the highest density. In the Western Himalayas, Jammu & Kashmir leads in both the number of villages and spring density.

• Importance of springs – Natural springs acts as a source of water for both drinking and irrigation.
  • In Himalayan region – It serves 64% of the cultivable land for irrigation.
• Reduction in springs – In the western Himalayas, over 45% have completely dried up in the past 4 decades.
• Over 26% have become semi-active, transitioning from perennial springs which depend on the monsoon.
• Cause of decline of Spring
  • Rising temperatures
  • Altered precipitation patterns
  • Decreasing snowfall and rainfall
• Impacts – The rural communities will face shortages in drinking water, agriculture, and daily household needs.

Reference

The New Indian express| Climatic Impacts on spring in the Himalayas