The Arctic Environmental Problems - New Ecoinformatics Tools in Environmental Science: Applications and Decision-making - page 539

every level, is the key problem of environmental monitoring. Each scale has speci c

landscape, vegetation cover, topography, character of both hydrophysical and
weather structures, and living elements. The discovery of the internal and external
correlations between these elements and other elements of the NSS makes it possible
to form the knowledge base for the Arctic Basin monitoring system.
Interactions between the arctic components of the global NSS were studied by
many authors (McCauley and Meier 1991; Kondratyev and Johannessen 1993;
Riedlinger and Preller 1991; Preller and Cheng 1999; Krapivin and Varotsos 2008).
The Angara/Yenisey river system of Siberia is considered as an example of these
interactions. The intensive industrial development of the Northern Russian terri-
tories has led to signi cant environmental changes in these regions (Morgan and

Codispoti 1995). The major quantities of pollution substances are brought to the
northern coast of Russia by the rivers, thus violating the ecosystems of the northern
seas. One such river system is Angara-Yenisey river system (AYRS).
The Yenisey river

fl flows northward to the Kara Sea along the boundary between

the western Siberian flood plain and the central uplands, draining an area of about

2.6 million km 2 during its 4,100 km length. The

fl

flow rate of the Yenisey into the
Kara Sea has large seasonal variations, averaging 19,800 m 3 /s, and as high as
130,000 m 3 /s during the spring run-off. The Angara, a major tributary, accounts for
about one fourth of the total

fl

flows swiftly northward from Lake Baikal for
about one third of its 1,850 km length, before turning westward, toward its con-
fl

fl ow. It fl

fluence with the Yenisey. Recognizing that major sources of the radionuclides
found in the Kara Sea, as well as other environmental pollutants, might lie in the
Siberian watersheds of the Yenisey and the Angara, a joint Russian-American
expedition was undertaken in July and August of 1995. The region where the
expedition was conducted includes the

five hydroelectric dams at Krasnoyarsk and
Sayano-Shushenskoye on the Yenisey and at Irkutsk, Bratsk and Ust-Ilimsk on the
Angara. The power output from these facilities has fostered rapid industrial growth
in this region. Krasnoyarsk is the major industrial city located on the upper reaches
of the Yenisey. Nearby is the nuclear production and processing facility,
Krasnoyarsk-26, which is situated approximately 270 km upstream of the

Angara-Yenisey junction. Along the Angara River, there are five cities with major

industrial activities: Irkutsk, Angarsk, Usolye-Sibirskoye, Svirsk and Bratsk. These
cities have facilities producing both radionuclides and chemical pollutants that can
contribute to the source terms in the two rivers.
Samples of Angara River water and sediments were taken, beginning from near
its source at Lake Baikal and continuing at selected sites of interest, downstream to
its junction with the Yenisey river, near the lumber processing village of Strelka.
Along the Yenisey sampling was conducted on both sides of the junction, begin-
ning upstream from just below the village of Kazachinskoye and continuing
downstream to the town of Lesosibirsk.
As is shown in Krapivin (1995), a complex evaluation of the pollution level in
the Arctic Basin as a whole, is possible by synthesis of a mathematical model of
pollutant transport by the rivers from adjacent territories.