Ganga, Brahmaputra, Indus water levels to rise by 2050: New IPCC report

Ganga, Brahmaputra, Indus water levels to rise by 2050: New IPCC report

TOPIC: Environment

Context- The Indus, Ganga and Brahmaputra river basins, which provide water to the most densely populated areas of south Asia, will see an increase in river ‘runoff’ by 2050 and 2100, according to projections by the IPCC in its Sixth Assessment Report on Impacts, Adaptation and Vulnerability, released February 28, 2022.

Concept-

• River run-off’ refers to water that comes into a river water system from sources such as rainfall, melting snow and groundwater.
• The run-off could increase 3-27 per cent by mid-century, according to the report.
• It would be:
  • 7-12 per cent in the Indus
  • 10-27 per cent in the Ganga
  • 3-8 per cent in the Brahmaputra
• The increase in run-off in the upper Ganga and Brahmaputra would be due to a rise in precipitation, while in the Indus, it would be due to accelerated melting snow.
• The Indus-Ganga-Brahmaputra region also faces the threat of increased frequency of flood events.

Ganga River:

• The Ganga originates as Bhagirathi from the Gangotri glacier in Uttar Kashi District of Uttarakhand at an elevation of 7,010 m.
• Alaknanda River joins Bhagirathi at Devaprayag. From Devapryag the river is called as Ganga.
• At Farraka, it bifurcates into Bhagirathi-Hugli in West Bengal and Padma-Meghna in Bangladesh (it ceases to be known as the Ganga after Farraka).

Brahmaputra River:

• It originates under the name of Siang or Dihang, from the Angsi glacier of the Kailash range near the Mansarovar Lake.
• It enters India west of Sadiya town in Arunachal Pradesh.
• Tributaries: Dibang, Lohit, Siang, Burhi Dihing, Tista, and Dhansari.
• The world’s largest riverine island, Majuli Island is on the Brahmaputra River in the state of Assam.
• The Brahmaputra drains into the Bay of Bengal before forming a huge delta along with the Ganga.

Indus River:

• It flows in north-west direction from its source (Glaciers of Kailas Range – Kailash range in Tibet near Lake Manasarovar) till the Nanga Parbhat Range.
• It is joined by Dhar River near Indo-China border.
• After entering J&K it flows between the Ladakh and the Zaskar Ranges. It flows through the regions of Ladakh, Baltistan and Gilgit.
• It is joined by the Zaskar River at Leh.
• Near Skardu, it is joined by the Shyok at an elevation of about 2,700 m.
• The Gilgit, Gartang, Dras, Shiger, Hunza are the other Himalayan tributaries of the Indus.
• Kabul river from Afghanistan joins Indus near Attock. Thereafter it flows through the Potwar plateau and crosses the Salt Range (South Eastern edge of Potwar Plateau).
• Just above Mithankot, the Indus receives from Panjnad (Panchnad), the accumulated waters of the five eastern tributaries—the Jhelum, the Chenab, the Ravi, the Beas and the Satluj.
• The river empties into the Arabian Sea south of Karachi after forming a huge delta.