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of cost-effectiveness, given the lower crop yields over
large areas. However, in the Griffith and Murrumbidgee
irrigation areas, the cost of hail suppression would
certainly be less than the losses experienced. To date,
the purpose of cloud seeding in Australia is usually not
for hail suppression, but for rain enhancement to relieve
drought in New South Wales, and to prevent bushfires
in Victoria.
Hail can be deadly. On two occasions since 1960,
hail has killed over 300 people in Bangladesh, which
experiences the most frequent and intense hailstorms
of any location in the world. Nothing, however, has
eclipsed the disaster that struck the army of Edward
III in 1359 near Chartres, France. In a matter of
minutes hail the size of goose eggs killed 1000 men and
6000 horses, effectively ending his campaign to take
France in the early years of the Hundred Years' War.
Hail is also destructive to crops, animals, buildings, and
vehicles. About 2 per cent of the United States' crop
production is damaged by hail each year. On the Great
Plains of the United States, losses in some years have
amounted to 20 per cent of the value of the crop. In
Australia in 1985, 20 per cent of the apple crop was
wiped out by a single hailstorm around Orange, New
South Wales. Following the drought of 1982-1983,
some wheat farmers in eastern Australia suffered the
misfortune of seeing bumper wheat crops destroyed by
hail. Property damage is less extensive than crop losses;
however, hailstorms are the major cause of window
breakage in buildings, and the major natural cause of
automobile damage. The largest single insurance
payout - made by the major international insurance
underwriter Munich Reinsurance Corporation -
occurred following the 12 July 1984 hailstorm that
struck the city of Munich, West Germany. This
company paid out $US500 million, mainly on damage
to automobiles.
Sydney, Australia, has the misfortune of being rec-
ognized as the hail capital of the world. Insurance
brokers in Australia call hailstorms 'glaziers' picnics'
because of the damage they do to windows. Here,
there is an additional risk to property because homes
are traditionally roofed with clay tiles that can be
broken by hail. Worse, low-cost public housing uses
fibrocement sheeting as exterior wall cladding.
Between 1980 and 1990, three or four localized storms
in the Sydney metropolitan area led to claims each
amounting to $A40-60 million. This was accepted as
the norm until two devastating events in the 1990s.
A)
Large hailstones that have built up quickly from the
aggregation of graupel particles (photo credit: Eric Beach,
28 April 2002, Pomfret, MD http://www.erh.noaa.gov/
er/lwx/publicpix/index.htm).
Fig. 4.6
B)
A layered hailstone created by hail passing through the
melting-freezing boundary at least five times
(photo credit: http://www.crh.noaa.gov/mkx/slid-
eshow/tstm/images/slide22.jpg).
Fig. 4.6
the United States, hail suppression programs were ter-
minated at the end of the 1970s because of political
controversy. The main reason was marginal evidence
that cloud seeding experiments actually increased the
amount of hail, especially if thunderstorms had
reached a mature or supercell stage. However, data
collected over a three-year period indicated that crop
losses had been reduced by 48 per cent in western
Texas and by 20 per cent in South Dakota. In Australia,
major hail suppression programs have not progressed
beyond the experimental stage. There is some question
 
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