Science Codex 12 November 2015: Gradual melting of winter snow helps feed water to farms, cities and
ecosystems across much of the world, but this resource may soon be
critically imperiled. In a new study, scientists have identified
snow-dependent drainage basins across the northern hemisphere currently
serving 2 billion people that run the risk of declining supplies in the
coming century. The basins take in large parts of the American West,
southern Europe, the Mideast and central Asia. They range from
productive U.S. farm land to war-torn regions already in the grip of
long-term water shortages.
Snow is an important seasonal water source mainly around large
mountain chains. From higher elevations, snowmelt runs gradually into
the lowlands during spring and summer growing seasons, when human demand
peaks. But global warming is upsetting this convenient balance. Studies
show that in many areas, more winter precipitation is falling as rain,
not snow, and washing away...
read on.
