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The North American Drought Monitor
and a Global Drought Early Warning System
Jay Lawrimore, Richard Heim and Tim Owen, NOAA National Climatic Data Center, USA;
Mark Svoboda, National Drought Mitigation Center, USA; Valentina Davydova,
Servicio Meteorólógico Nacional, Mexico; Dwayne Chobanik, Agriculture and Agri-Food Canada,
National Agroclimate Information Service; Brad Rippey, US Department of Agriculture;
and Doug LeComte, NOAA Climate Prediction Center, USA
W
ater availability is emerging as a critical concern for
the 21st century. While drought is a recurring phenom-
ena that has plagued civilizations throughout history,
today it is one of the world’s most costly and far-reaching natural
hazards. In many countries, such as Australia, China, and the
United States, drought occurs over a portion of the country each
year. Even in countries such as Brazil where tropical climates
dominate, drought is a recurring and costly event.
There are warnings of potential increases in the
frequency and intensity of droughts as a consequence
of climate change. This expected change in drought
climatology, coincident with population increases and
other factors such as health crises, conflict, and unsus-
tainable use of natural resources (especially water)
combine to magnify drought’s impacts. While the world’s
poorest people most frequently and severely feel the
effects of drought, it has a universal impact on natural
habitats, ecosystems, and the economies and societies
within both developed and developing nations.
In the US drought affects more people than any other
natural hazard and it is one of the most costly, with
direct losses that average between USD6 to 8 billion each
year.
1
In Mexico, 78 per cent of the federal funds spent
by the program of Attention to Natural Disasters and
Climatological Contingencies between 1995 and 2005
was directed to combat the effects of drought.
Furthermore, a new response and planning strategy for
the period of 2007 to 2012 is being developed as part of
the National Hydric Program (Programa Nacional
Hidrico).
On the continent of Australia, drought has affected
the most heavily populated areas since 2001, with severe
precipitation deficits in 2002 and 2006 helping to rank
the past six years alongside 1895 to 1903 and 1938 to
1946 as eastern Australia’s most severe long-term
droughts since European settlement.
2
The long-term
increase in temperature has worsened the severity of
drought in Australia,
3
as it has on other continents, and
within the past 30 years there is evidence of an increase
in the incidence of drought worldwide.
4
On the continent of Africa, the combination of arid
climates and variable rainfall patterns leaves many
nations extremely vulnerable to drought and climate
change is expected to magnify these problems.
5
Between
1980 and 2000, drought killed more than two million
people in Ethiopia, Sudan and Mozambique alone.
Almost one million of them died in the Ethiopiaan
famine of 1984. Beyond the human cost, drought in
Observations from in situ observing systems, satellite, and radar are essential for
drought monitoring; included among key measures of drought are temperature,
precipitation, streamflow, snow pack, reservoir levels, and groundwater
Photo: Brad Udall
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