How do snow and glaciers in Pakistan's northern mountains support the Indus River system?

The snow and glaciers in Pakistan's northern mountain ranges—specifically the Karakoram, Hindu Kush, and Himalayas—are vital to the Indus River system, providing a significant portion of its water supply.1

These mountains act as a massive reservoir, where precipitation often falls as snow. The subsequent melting of this snow and glacial ice feeds the Indus and its tributaries, such as the Shyok, Shigar, and Gilgit rivers. This meltwater is essential for maintaining the river's flow, particularly during the spring and early summer months (March to June) when the water levels begin to rise.1234

While the monsoon season (July to September) provides additional water, the consistent contribution from glacial and snowmelt is a fundamental component of the system's hydrology. However, climate change has increasingly impacted these glaciers, leading to earlier melting and overall shrinkage, which poses long-term risks to the stability of the water supply for the region.5416