A new report published in the online journal PLoS ONE, analyzing
water consumption in 405 river basins around the world, found that water
scarcity impacts at least 2.7 billion people for at least one month
each year.
“Freshwater is a scarce resource; its annual
availability is limited and demand is growing,” said Arjen Hoekstra,
professor in water management at the University of Twente and lead
author of the report, Global Monthly Water Scarcity: Blue Water Footprints versus Blue Water Availability. “There
are many places in the world where serious water depletion takes place:
rivers running dry and dropping lake and groundwater levels.”
The
new assessment of global water scarcity tracked month-to-month
variability in water flows and accounted for the flows needed to sustain
critical ecological functions. Through detailed analysis of the
total water consumption, or depletion, rather than water withdrawals,
the study highlights how the water used to grow crops, sustain industry
and provide drinking water has in many places exceeded sustainable
levels of water use.
Ninety-two percent of humanity’s
total water footprint is for agriculture, and irrigated agriculture
depletes more water than cities and industries. Study co-author Brian Richter, Director of The Nature Conservancy’s Global Freshwater Program,
explained, “Cities use more water than crops on a per-area basis, but
it's important to note that irrigated agriculture occupies four times as
much land as cities do. We need to help farmers implement
state-of-the-science irrigation methods and improve the productivity of
rain-fed farms as soon as possible. We are going to have to produce more
food with less water.”
Researchers from the University of Twente, Water Footprint Network, The Nature Conservancy
and WWF studied river flows in 405 river basins between 1996-2005.
Their analysis showed that 201 river basins supporting 2.67 billion
people experienced severe water scarcity during at least one month of
the year.
“In places with multiple months of scarcity, they
are likely experiencing serious competition for water,” said Richter,
“and during droughts they’ll have economic impacts in agriculture, power production or other industries.”
“This
assessment gives a more detailed and complete view of the relationship
between the water footprint – the amount of water consumed in the
production of goods and services – and the growing problems of water
scarcity and the resulting environmental, social and economic losses,”
said Ruth Mathews, Executive Director of the Water Footprint Network.
“Through cooperation between governments, investors, companies, farmers
and environmental organizations, we can take direct action to improve
the sustainability, efficiency and equitability of water use ensuring
that we can feed people and sustain healthy ecosystems in the future.”
Read More@nature.org
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