The findings may indicate global warming could potentially threaten future supplies of food and water.

Scientists from the National Center for Atmospheric Research examined stream flows from 1948 to 2004, and found significant changes in about one-third of the world’s largest rivers.

The waterways that were delivering less water to large populations included the Colorado in the southwestern United Sates, the Ganges in India, the Yellow River in northern China and the Niger in West Africa.

More evaporation due to higher temperatures and decreased precipitation in the mid- and lower latitudes may be responsible for the reduced flows, the scientists say.

Streams near the Arctic ocean were found to be producing greater flows because of rapidly melting ice and snow due to a warming climate at higher latitudes.

The results will be published in the American Meteorological Society's Journal of Climate.

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