Fourth Study Conference on BALTEX Scala Cinema Gudhjem

- 188 -
Analysis of Water Quality Changes and Hydrodynamic Model of Nutrient
Loads in the Western Dvina / Daugava River
Vladimir Korneev 1 , Ryhor Chekan 2
1
Central Research Institute for Complex Use of Water Resources (CRICUWR), ½ Slavinskogo Str., 220086, Minsk, Republic
of Belarus, tel. +375-172-63-48-33, fax +375-172-63-48-33, e-mail: cricuwr@infonet.by, v_korneev@yahoo.com
2
Republican Hydrometeorogical Centre , 110 Skaryna Avenue, 220023, Minsk, Republic of Belarus, tel. +375-172-64-03-20,
fax +375-172-64-03-35, e-mail: chek@by.mecom.ru
1. Physiogeographical description of the
Western Dvina/Daugava River basin
The Western Dvina River crosses the territory of three
countries: Russia, Belarus and Latvia. Near Riga it flows
into the Baltic Sea. The river has a length of 1,003 km
with a drainage area of 87,800 km 2 . A small part of the
basin is located in Lithuania and Estonia. In Latvia, the
river is called Daugava. According to the classification
of the Water Framework Directive, the Russian and
Belarussian parts (= Dvina) belong to the ‘Eastern
Plains’, while the Latvian part (= Daugava) belongs to
the Baltic Province.
Anthropogenic impacts on the river are moderate. They
are mainly due to pollution from domestic, industrial
and agricultural point and non-point sources.
2. The changes of nutrient loads along the
Western Dvina River
The analysis of the change of nutrient loads along the
Western Dvina River are based on the assessment of
monitoring data from 1995-2000. The Department on
Hydrometeorology of the Ministry of Natural Resources
and Environmental Protection of the Republic of Belarus
maintains monitoring activities of quantitative and qualitative
water parameters in the Western Dvina river based
on a set of hydrological and hydrochemical observations.
The hydrological stations provide for standard
measuring techniques of the hydrological regime (daily
observations of water level and water discharge at applicable
points). Samples at hydrochemical stations are
taken 6 to 12 times per year. About 50 parameters are
measured. The monitoring system of the Western Dvina
River Basin is shown in Figure 1.
Figure 1. Belarusian part of the monitoring system of
the Western Dvina River Basin.
Concentration (mg/l)
Concentration (mg/l)
Concentration (mg/l)
1,2
1
0,8
0,6
0,4
0,2
0
Verchnedvins
NH4-N (average per year) Western Dvina
NO2-N (average per year) Western Dvina
Novopolots
Vitebsk
Suraj
0,04
1995
0,035
1996 1997 1998 1999 2000
0,03
0,025
0,02
0,015
0,01
0,005
0
0,035
Verchnedvins
PO4-P (average per year) Western Dvina
Novopolots
Vitebsk
Suraj
0,03 1995 1996 1997 1998 1999 2000
0,025
0,02
0,015
0,01
0,005
0
Verchnedvins
Novopolots
Vitebsk
Suraj
1995 1996 1997 1998 1999 2000
Figure 2. Changes of annual nutrient components at
the main monitoring stations along the Western Dvina
based on the State Water Cadastre data.
The concentrations of nutrient components in the Western
Dvina and its tributaries oscillate around the fixed
maximum admissible concentrations (MAC) accessible
in Belarus. The values of Belarussian MAC of nutrient
components are comparable to EU - standards. The river
Western Dvina in Belarussian part can be considered as
moderately polluted.
The component-wise assessment of the share of loads
from point versus diffuse sources shows, that the point
sources contribution ranges between 18% and 32 % of
the total pollution load (on the whole part of Western
Dvina River on the territory of Belarus). The remaining
part are loads from diffuse sources.