Living
With Drought
Australia
is the driest inhabited continent even though some areas have annual
rainfall of over 1200 millimetres. Our climate is highly variable -
across the continent generally, as well as from year-to-year. We must
learn to live with drought!
Drought
is ... ?
Drought's
impacts
Its
causes?
Managing
drought
Types
of drought
Global
monitoring
The
effects of major drought
Drought
is ... ?
A drought is a prolonged, abnormally dry period when there is not enough
water for users' normal needs. Drought is not simply low rainfall; if
it was, much of inland Australia would be in almost perpetual drought.
Because people use water in so many different ways, there is no universal
definition of drought. Meteorologists monitor the extent and severity
of drought in terms of rainfall deficiencies. Agriculturalists rate
the impact on primary industries, hydrologists compare ground water
levels, and sociologists define it on social expectations and perceptions.
Drought's
impacts
During climate extremes, whether droughts or flooding rains, those on
the land feel it most. Agriculture suffers first and most severely -
yet eventually everyone feels the impact. Drought disrupts cropping
programs, reduces breeding stock, and threatens permanent erosion of
the capital and resource base of farming enterprises. Declining productivity
affects rural Australia and the national economy. The risk of serious
environmental damage, particularly through vegetation loss and soil
erosion, has long term implications for the sustainability of our agricultural
industries. Water quality suffers, and toxic algae outbreaks may occur;
plants and animals are also threatened. Bushfires and dust storms often
increase during dry times.
Its
causes?
Australia has one of the most variable rainfall climates in the world.
Over the long term we have about three good years and three bad years
out of ten. These fluctuations have many causes, but the strongest is
the climate phenomenon called the Southern Oscillation. This is a major
air pressure shift between the Asian and east Pacific regions - its
best-known extreme is El Niño. In recent years, the Bureau of Meteorology's
greater understanding of El Niño has improved its ability to predict
seasonal rainfall and help authorities and individuals with early drought
warnings. More information is in the Bureau's brochure Climate Variability
and El Niño, or on the World Wide Web at /
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