The study was conducted jointly by research organisation FutureWater, Netherlands' Utrecht University and the Kathmandu-based International Centre for Integrated Mountain Development.
"Our results show that the river flow will increase at least until 2050, despite retreating glaciers," researcher Arthur Lutz said in a statement today.
"The glaciers feeding Indus river, although retreating, will generate increasing amounts of meltwater in the coming decades due to higher temperatures. For the other rivers, the increase in river flow is mainly caused by increasing precipitation," the researchers said.
Glacier and snowmelt contribute water to ten important river basins originating from the Himalayas and in the Tibetan plateau serving over 1.3 billion people.
The group of scientists assessed the importance of meltwater for Indus, Ganga, Brahmaputra, Salween and Mekong rivers and discovered how climate change will alter river flow in the coming decades.
The findings of the study will be important in shaping climate change adaptation policy in the 12 riparian countries surrounding these river basins.
Co-researcher Walter Immerzeel said, "These results confirm on a larger scale what we already discovered last year for two small watersheds in the Indus and Ganga basins".
The scientists emphasise that their projections are only until 2050. Scenarios for the distant future, or until the end of the century, remain uncertain, in particular for Indus river where meltwater is most important.