The Arctic Environmental Problems - New Ecoinformatics Tools in Environmental Science: Applications and Decision-making - page 544

¼ H 7 ;m þ H 10 ;m H 2 ;m

y k @ S k ;m =@ t þ v u @ S k ;m =@u þ v k @ S k ;m =@k

ð 6 : 25 Þ

ln 2
t m

H 9 ;m H 11 ;m y k S k ;m

where H 1, ʽ is the rate of radionuclide washing away from the soil with fl ow K, H 2, ʽ

is the radionuclide input to the river from the ground water with ow J, H 3, ʽ is the

transport of the radionuclide to the area X k through the boundary of Ω by the AYRS
tributaries, H 4, ʽ

fl

ows U, F and M; H 5, ʽ is the
radionuclide sedimentation to the river bottom by gravitation and with the dead
biomass of the river ecosystem; H 6, ʽ is the washing away of the radionuclide from
the sediments; H 7, ʽ is the radionuclide leakage to the ground water with

is the radionuclide carried out with fl

ow R; H 8, ʽ
is the anthropogenic source of the radionuclide; H 9, ʽ is the radionuclide input to the
soil from the ground water by

fl

fl ow N; H 10, ʽ is the radionuclide washing out form

the soil to the ground water by P fl ow; H 11, ʽ is the radionuclide losses by sedi-

mentation in the ground water; and H 12, ʽ is the radionuclide input by rain. The

quantities D k ¼ q k r k C k , y k ¼ r k G k , D k ¼ l k ð 1 q k Þ r k and w k ¼ r k q k r k , where

l k is the thickness of the ef cient soil layer on the area X k , and r k is the thickness of

the sediment layer.
The , 12) are parameterized by linear models according to the

papers of Krapivin (1995) and Nitu et al. (2000a). The BIO and CPK blocks are
described by similar balance models in analogy with the models described by
Somes (1999) and Kram (1999). The AYRS biology is given in the form of a
scenario or is described by the model of Legendre and Krapivin (1992). The

fl ows H i, ʽ (i =1, …

ows
of heavy metals include an assimilation of dissolved fractions by plankton H Z
w

fl

, the sedimentation of solid fractions H e , the absorption
from sediments by living elements H e ;w

and by nekton H F
w

, sedimentation with the dead organic matter

and the discharge from sediments H e ;w

by erosion, digenesis, turbulence and
anthropogenic impacts. The balance equations taking these

H D
w

fl flows into account have

the same form as the Eqs. ( 6.22 ) ( 6.25 ):

-

¼ X

3
i¼1 a

D k @

t þ l k @

e w
@

e w
@

i

2 Q i e ;w H e þ a 1 H e ;w

ð 6 : 26 Þ

x

D k @w w
@ t þ l k @w k

¼ ð 1 a 1 Þ H e ;w H Z

w H D

ð 6 : 27 Þ

w

@ x

e
@ t ¼ H e a 1 H e ;w þ H e ;w

w k @ ð 6 : 28 Þ

w k @w

t ¼ H D

w ð 1 a 1 Þ H e ;w þ H e ;w

ð 6 : 29 Þ

@