Vienna, April 16 (DPA) The world’s population and
agriculture hotspots are particularly sensitive to changes in the
capacity of mountains to store water, geological scientists say. Both
naturally occurring and man-made climate factors are affecting the
capability of the world’s mountain ranges to serve as sources for
freshwater for adjacent lowlands. According to a recent study, about 7
percent of the world’s mountains are essential for providing downstream
supply, said Daniel Viviroli of the University of Berne.
This number is likely to increase, as 37 percent provide an important
supply that will grow more important in years to come. The dryer the
lowland climate gets, the more important the mountains become, Vivrioli
said.
“If we want to know about the consequences for arid and semiarid areas,
we need to be aware of the runoffs,” he said, speaking on the sidelines
of the annual meeting of the European Geosciences Union in Vienna.
Precipitation runoff from the world’s mountain ranges are the main
contributor to freshwater resources in the surrounding lowlands and are
essential for agriculture or drinking water.
“Pressure on resources will increase in the subtropics, arid and
semiarid regions,” he said.
Current research on climate change predicts that “wet places will get
wetter and dry places will get dryer,” climatologist Philip Mote from
the University of Washington said.
Temperature increases have triggered a string of knock-on effects, said
Carmen de Jong of France’s University of Savoy, who investigates
mountain hydrology in the European Alps.
“Everything is being pushed higher,” she said. Snow levels were moving
up ever higher in the mountains, and tourism is following. Less water
from snow and glaciers means less water in reservoirs, while ever more
was needed for the tourism industry, likely to offset the fragile
balance of mountain ecosystems.
“We observed a decrease of water surcharges since 1985,” de Jong
said.At the same time there has been an exponential increase in water
needs. This could turn into a vicious circle, the scientists feared.
Water consumption is expected to increase because of increased
temperatures, while at the same time resources were dwindling because
of the warmer climate, which was likely to decrease precipitation and
increase evaporation.
One aspect the scientists pointed out was the shift of the timing of
snowmelts, which were a major source of freshwater for lowland streams
in dry summer months.There could well be the same amount of water
coming down from a mountain, but with an earlier onset of the snowmelt,
the timing was off for farmers, Mote said.
One group feeling the effects of water coming from the mountains’
melting snow covers each summer would be farmers: up to 70 percent of
the world’s freshwater use goes into food production.The problem was
less removed than people might believe, de Jong said.
“People have problems, but often they are local,” she said. “People
think they are alone with their problems.”
Scientists had by now figured out the natural effects in a mountain’s
water system, but little data was available as of yet on
human-generated effects.
“We don’t know what is going on,” de Jong said.
The question whether there would be enough water stored in the world’s
alpine water towers 50 years down the track could not be answered that
easily, Mote said.
“It depends on where you are. South of 50 degrees latitude there will
be questions about water supply,” he said.
In the hotspots, the water resource balance was likely to “go the wrong
way,” Mote said.
The problem that needs to be tackled is global, the scientists warned.
“All mountain areas have the same problem,” de Jong said.
Even in Europe’s Alps, probably one of the epitomes of snow-covered
slopes and lush, green hills, ground-water levels in some regions
dropped by 25 percent over the past 100 years.
“There are no water management strategies now,” de Jong warned of the
dry times ahead.
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