U.S. Water News Online
MANHATTAN, Kan. -- In wide-open western Kansas, rain and
hail are serious business with an impact on every wallet. But
attempts to alter such weather are meeting increasing controversy.
Nay-sayers think past attempts to reduce hail damage have limited
vital rainfall. Yea-sayers believe history has shown cloud seeding
brings sizeable benefits.
Recent research at Kansas State University indicates, however, the
facts aren't clear-cut. So far, no one can truly measure what happens
when humans try to interject a kick in weather's get-along.
Since 1975, the Western Kansas Weather Modification Program
(WKWMP) has been seeding clouds to suppress hail and promote rain in
southwestern Kansas. In 1997, the program expanded into northwest
Kansas and became the largest aviation-based cloud-seeding program of
its kind in the nation.
Roughly 55 percent of last year's WKWMP funding came from
individual counties and groundwater management districts in western
Kansas. The balance came from the state.
By 1998, however, northwest Kansas had a new group -- the
Concerned Citizens for Natural Weather -- organized to formally
oppose cloud seeding.
"Given what's known now, neither side in the debate is right ...
or wrong ... or likely to change its mind," said K-State Research and
Extension economist Terry Kastens. "Opponents have some scientific
backing for their anti-seeding stance, but an equal amount of
research refutes their claims."
The modern science of weather modification emerged shortly after
World War II. It was an offshoot of General Electric's attempts to
prevent icing on aircraft wings.
"Science got promising results in the lab. Its results were more
ambiguous when applying the technology to actual clouds," said Brian
Vulgamore, who conducted K-State's study as part of his graduate
degree program and now farms near Scott City, Kan. "Unfortunately,
science was unable to separate fact from fiction after that, due to
lack of research funding in the 1980s and '90s."
That's why his study bypassed the science of modifying the
weather. Instead, Vulgamore tried to assess real-life impacts. He
examined both rainfall and hail in western Kansas and worked to put
their outcomes in dollar terms.
"The smallest drought causes economic harm in any semi-arid
farming region," Kastens pointed out. "Up to a point, extra rainfall
brings extra economic benefits."
But equal precipitation losses and gains don't bring equal
results. Vulgamore's analyses suggest that an added inch of
growing-season rain in western Kansas translates into an economic
gain of about $18 million. A 1-inch loss in rainfall translates into
economic losses exceeding $19 million.
Even so, this finding provided little insight, because the study
"This doesn't mean the WKWMP hasn't had an economically
significant impact on the moisture supply. It merely demonstrates the
difficulty in measuring impacts of this kind. Statistics couldn't
prove undeniable results because western Kansas naturally has widely
variable weather," Vulgamore said.
To assess the other half of the WKWMP mission, K-State's study
looked at the dollar losses of hail-damaged crops. Vulgamore compared
every western Kansas county's long-term loss average with its average
for the cloud-seeding period.
He found that while the WKWMP was at work, individual counties
within the program's target area had seen significant drops in
hail-related damage. Many counties east of the target area also had
recorded sizeable damage declines, suggesting a possible downwind
effect. Yet, several Kansas counties north and south of the target
area saw large damage cutbacks, too.
Vulgamore then grouped the counties by whether they'd participated
in the program. He found that on average, the target area counties
had shown a 15 percent greater drop in hail-related crop loss.
"Keeping that 15 percent in perspective is important," Kastens
said. "Given the wide variability in western Kansas weather, the
difference between the target and non-target counties could have been
a matter of normal, natural hail patterns. Besides, we can't say with
statistical confidence that the WKWMP is responsible for the
15-percent drop. The WKWMP would have had to reduce hail damage by
nearly 60 percent before statistics could say the change pointed
straight to cloud seeding as a cause.
"Even so, Brian's analyses indicate that if the WKWMP reduced
yield losses by 3.5 percent, it paid for its own program costs. In
fact, if you consider the hail damage of buildings, equipment and
other property, the amount of saved crop yield needed to make the
program pay would be even less."
On the whole, Vulgamore is optimistic about the potential for
"Although assessing its effects with confidence will require much
more research by physical scientists, I would hate to completely shut
the door on this technology," he said. "I believe the most promising
aspect of weather modification is its relatively small cost, compared
to the potential return."
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