Groundwater Vulnerability and Protectability to Chernobyl-Born Radionuclide - Groundwater Vulnerability: Chernobyl Nuclear Disaster - page 95

to the upper aquifer assessment depth z 1 *. The plots shown in the figure corre-
spond to the indicated values of vertical flow velocity w .
Further on, according to the procedure described in Section 4.2, maps were
drawn of the low-permeability confining layer thickness m 0 (Figure 5.9) and
calculated vertical flow velocity w (Figure 5.10) according to data taken from the
3D model of the Kyiv region [ Rudenko et al ., 1997; Shestopalov et al ., 1997].
The thickness m 0 of the low-permeability layer within the model area vary from
0 to 50 m, and values of vertical flow velocity w vary from −3 × 10 −4 to +2.2 × 10 −3 m/day.

Pripyat

Thickness of Kyiv marls, m
0-5
5-15
15-25
25-35
35-45

Chernobyl

45-55

Irpen

Brovary

Kyiv

Borispol

Boyarka

Berezan

Vasilkov

Obukhov

Pereyaslav-khmelnitsky

0 10 20

km

blk

Figure 5.9 Map of the low-permeability layer (Kyiv marl) thickness m 0 taken from 3D
hydrogeological model of the Kyiv region [ Rudenko et al ., 1997; Shestopalov et al ., 1997].