Fires in Nature - Natural Hazards - page 145

year. The destruction only got worse - with 73 880 km 2
and 64 040 km 2 of forest going up in smoke in 1989
and 1994, respectively. The magnitude of this burning
was matched along the Amur River (separating China
and Siberia) by the Great Black Dragon Fire of 1987,
which burnt through 73 000 km 2 , killed 220 people and
left 34 000 homeless. The areas of these last three fires
are equivalent to the area of Scotland, and are 13 times
larger than the Yellowstone Fire of 1988.
All of these fires pale in significance when compared
to the Great Siberian fires of July-August 1915. In that
year, up to 1 million km 2 of Siberia, from the Ural
Mountains to the Central Siberian Highlands, burned
(an area 2-20 times greater than the extent of the 1980
fires in Canada). An area the size of Germany, covering
250 000 km 2 , was completely devastated between the
Angara and Lower Tunguska Rivers. These gigantic
fires were brought about by one of the worst droughts
ever recorded in Siberia. Most of the taiga and larch
forests were desiccated to a combustible state, produc-
ing crown fires. Over 500 000 km 2 of peat dried out
and burnt to a depth of 2 m. The amount of smoke
generated was 20-180

51 000 km 2 , and 50 000 km 2 , respectively, of rainforest
burnt across Indonesia, mainly in Kalimantan. During
the 1997-1998 ENSO event, smoke due to slash-
and-burn agriculture, forest clearing, and firing of
peatlands enveloped over 100 million km 2 of South-
East Asia in an acrid, pea-soup haze that reduced
visibilities to 2-100 m. At one point the pollution
reading at Pontianak in west Kalimantan reached
1890 mg m -3 , 40 times the level considered safe by the
World Health Organization. In Indonesia, about one
million people suffered health problems and 40 000
had to be hospitalized. At one school, visibility was so
low that school children had to be roped together
to keep them from getting lost. About 2.6 10 9 tonnes

of carbon - 1000 times more than produced by the
Siberian fires of 1915 - were released into the atmo-
sphere, an amount equivalent to 40 per cent of global
emissions that year from fossil fuels. Because of
reduced visibility, two ships collided in the Straits
of Malacca, killing twenty-nine people. The haze was
also implicated in the crash of a Garuda Airbus into
a mountain at Medan with the loss of 234 passengers
and crew. Ultimately, 7000 professionals and 31 000
volunteers fought the fires. As Indonesia's resources
became overwhelmed, the international community
responded with cash donations, medical assistance,
and firefighting expertise at a level usually reserved
for a major earthquake or drought. Indonesia's gross
national product dropped 2.5 per cent due to the
decline in its tourist and forest industries.

10 6 tonnes, a figure equivalent
to the amount of smoke estimated to be produced in a
limited-to-extreme nuclear war leading to a nuclear
winter. Thick smoke was lifted more than 12 km into
the sky. In the immediate area, visibility fell to 4-20 m
and to less than 100 m as far as 1500 km away. As a
result, the solar radiation flux was significantly attenu-
ated at the ground, dropping average temperatures by
10°C. At the same time, long wave emission at night
was suppressed such that the diurnal temperature
range varied by less than 2°C over a large area. These
below-average temperatures persisted for several
weeks; however, harvests in the area were delayed by
no more than two weeks. Little evidence of the fires
was detectable outside Siberia. Because of the isolation
of the area and the low population density, reported
loss of life was minimal. The above documentation of
large fires implies that conflagrations of this magnitude
are frequent occurrences in the boreal forests of the
northern hemisphere. Forest fires presently pose
the most serious natural hazard in the two largest
countries of the world, Canada and Russia.
Nor are fires restricted to temperate latitudes. Since
1980, large fires have swept through the tropics of
Indonesia and Amazonia, exacerbated by ENSO
events and human malpractice. During the 1982-1988,
1994, and 1997-1998 ENSO events, 32 000

Unit ed States

(Pyne, 1982; Romme & Despain, 1989; Firewise, 1992;
ThinkQuest Team, 2001)

Fire history

In North America at least 13 fires have burned more
than 400 000 hectares. In the twentieth century, almost
all such mega-fires have begun as controlled burns, or
as wildfires that at some point could be considered
controllable. And almost all severe fire seasons were
preceded by drought. The intensity of any fire is not
necessarily dependent upon the growth of biomass
during wet seasons, but on the availability of dried
litter or debris generated by disease or insect infes-
tation, on windstorms, previous fires, or land clearing.
This point is well-recognized. For example, the 1938
New England hurricane mentioned in Chapter 2 left a
trail of devastation in the form of uprooted trees and km 2 ,