Geoscience Reference
In-Depth Information
6.4.5 Simulation of Dispersion Processes for the Water
Pollutants
The block PSM simulates the pollution processes over the territory
Ω
as a result of
the atmosphere transport, river and surface coastal out
ow, navigation, and other
human activity. The variety of pollutants is described by three components: oil
hydrocarbons O, heavy metals (e
fl
solid particles,
w—
dissolved fraction) and ra-
dionuclides
. It is supposed the pollutants get into the living organisms only
through the food chains.
The rivers bring a considerable contribution to the level of pollution of the arctic
waters. The concentration of pollutant
ʵ
ʺ
in the river
ʳ
is
c j
. The pollutant
ʺ
enters
compartment
Ω ijk ∈ Ω R with the velocity c c
re
fl
ecting the mass
fl
flow per unit time.
Ω
Subsequently, the spreading of the pollutant in
is described by other sub-blocks.
The in
fl
uence of water exchanges between the Arctic Basin and the Paci
c and
Atlantic Oceans on the pollution level in
is described by block MPT. It is
supposed that the watersheds of the Norwegian Sea
Ω
X N and the Bering Strait
X B are
characterized by currents with varying directions given as a scenario.
The atmospheric transport of heavy metals, oil hydrocarbons and radionuclides
is described by many models (Phillips et al. 1997; Payne et al. 1991; Sportisse
2000). The application of these models to the reconstruction of the pollution dis-
tribution over
Ω
makes it possible to estimate optimal values of
ʔφ
,
ʔʻ
and the step
in time
t. The present level of the database for the Arctic Basin provides for use of
a one-level Euler model with
ʔ
(block APTM). It is
supposed that pollution sources can be located on the Arctic basin boundary. Their
detailed distributions are given as the SSMAE input. The transport of pollutants to
the Arctic Basin and the formation of their spatial distribution are realized in
conformity with the wind velocity
ʔ
t = 10 days,
ʔφ
=
ʔʻ
=1
°
field, which is considered as given (Krapivin and
Phillips 2001b).
It is postulated that the oil hydrocarbons O(t,
,z) are transformed by the
following processes (Payne et al. 1991): dissolving H O , evaporation H O , sedi-
mentation H O , oxidation H O , biological adsorption H O , bio-sedimentation H O , and
bacterial decomposition H O . The kinetics equation for the description of the
dynamics of the oil hydrocarbons in the Arctic Basin is given by
φ
,
ʻ
z 2 X
7
2 O
@
z ¼ Q O þ k 2 @
t þ v w
=@u þ v w
=@k þ v z @
H i O ;
@
O
=@
u @
O
k @
O
O
=@
ð 6
:
10 Þ
i¼1
where Q O is the anthropogenic source of the oil hydrocarbons.
The process of the diffusion of the heavy metals in the seawater depends on their
state. The dissolved fraction of the heavy metals (
) takes part in the biogeo-
chemical processes more intensively than the suspended particles (e). But as sus-
pended particles, the heavy metals fall out more rapidly to the sediment. A
description of the entire spectrum of these processes in the framework of this study
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