Water Quality Monitoring in Russian Rivers
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2
Material and Methods
2.1
Study Site
The Oka River is a major tributary of the Volga River, the biggest stream in
Europe. The Oka River drains an area of about 73 700 km 2 • The annual mean
discharge before the Moskva influx is approx. 380 m 3 s· l • The width of the Oka
River in the mouth region is between 375 and 425 m. The depth ranges from 5 to
10m. The Moskva River is a major tributary of the Oka River. The annual mean
discharge into the Oka River is approx. 109 m 3 s· l • The Moskva River drains an
area of about 17 600 km 2 including the Moscow region. The width of the Moskva
River in the mouth region is between 120 and 175 m. The depth ranges from 2 to
9 m. During spring flood the water level can rise by 4 m. The average annual
temperature is 3.5 dc. The average annual precipitation in the area is about 700
mm.
2.2 Methodology
Samples were taken on a regular basis at five selected sampling points in the
mouth region (Fig. I). The sample points were located at the Oka River upstream
(sampling point Fig. 1 A) and downstream (Fig. 1 B, C) of the mouth region and
at the Moskva River upstream of the City of Kolomna (Fig. 1 D) and close to the
river mouth (Fig. 1 E).
In addition to the sampling in the mouth region, longitudinal concentration
profiles of pollutants for both streams were determined. The longitudinal profiles
covered approx. 110 km of the Moskva River and 250 km of the Oka River (Fig.
2). Overall, 48 sampling points were sampled including all major tributaries of
both rivers in this area.