This field research was made possible due to the grant extended by the Canadian International Development Agency (CIDA) and administered by the International Development Research Center (IDRC), Ottawa, Canada.

The first comprehensive field research (October 2000), coordinated in time with the similar expedition in Ukraine, allowed to estimate the transboundary pollution, to identify the major contaminating substances and to reveal the acutest problems in the region. However, that expedition was conducted within a very short time period, besides it had a number of specific features: no large-scale research of water radioactivity and a pre-scheduled Russian expedition never took place.

The spring-summer expedition of 2001 (May 19-June 12, 2001) was aimed to obtain both hydro-chemical and hydro-biological information from cross-section with intensive anthropogenic impact and the data on water runoff and water quality in the trans-boundary Russian-Belorussian and Ukrainian-Belorussian cross-sections, including the data on radioactive pollution.

The field research data on surface water quality in the Dnipro Basin estimated by their hydro-chemical and hydro-biological indicators will be of interest and immediate use for local regulatory institutions of nature protection, these data will also be instrumental for the research institutions in terms of comparing them with the available stationary observation data. Besides, the fact of additional water quality study in transboundary cross-sections will testify to a special attention paid by the three neighboring countries to the Dnipro River condition and rehabilitation, and will allow to work out recommendations on unifying three countries’ monitoring systems and developing coordinated (harmonized) methodology of establishing and measuring water quality indicators.

Expedition participants:

-  CRICWU (Central Research Institute of Complex Water Use) ;

-  Center for Radiation Control and Environmental Monitoring (CRCEM) of the State Committee for Hydrometeorology;

-  Brest, Vitebsk, Gomel and Mogiliov Oblast Committees and Minsk City Committee for Natural Resources and Environmental Protection;

-  Central Laboratory of the Ministry of Natural Resources and Environmental Protection;

-  Belarus State University;

-  Mozyr’ Pedagogical Institute.

Laboratory research was conducted in the licensed laboratories, namely:

-  Laboratories of Minsk City, Brest, Vitebsk, Gomel and Mogiliov Oblast Committees for Natural Resources and Environmental Protection (hydro-chemical indicators of water quality) and of Pinsk Town District Inspection;

-  Laboratory of the Center for Radiation Control and Environmental Monitoring (some hydro-chemical indicators, radio-activity tests, biological indicators);

-  Central Hydro-chemical Laboratory of the Ministry of Natural Resources and Environmental Protection (bottom sediment pollution analysis, biota analysis, hydro-chemical indicators of the control/baseline water sample);

-  Laboratory of Belarus State University (some biological indicators and radio-active pollution studies).

The expedition objectives were:

-  to conduct a simultaneous study of water quantity and quality in the Dnipro Basin during the spring to identify the most polluted/contaminated parts of the river and its main tributaries;

-  to compile the list of major indicators of surface water quality, i.e. those indicators which revealed pollutant and contaminant concentrations exceeding the admissible levels during the study period;

-  to work out recommendations on improving the network of trans-boundary monitoring observation stations;

-  to give a preliminary estimation of the trans-boundary water contamination.

The expedition tasks were:

-  to obtain the data on water runoff, hydro-chemical, hydro-biological and radiation indicators of water quality and bottom sediment in transboundary cross-sections and downstream of the major contamination sources;

-  to conduct field work and laboratory research for the list of sampling points, sampling time, list of indicators and measurement methodology coordinated with the Russian and Ukrainian expeditions;

-  to summarize and analyze the expedition results and work out recommendations on improving the monitoring system and trans-boundary contamination assessment.

Characteristics of the 2001 expeditions did not differ much from those of the 2000 expedition and were as follows:

-  conformity of the research (in time, space and applied methodology) with the similar work in the territory of Ukraine and Russia;

-  simultaneous registration of water quantity and quality in the river cross-sections under study;

-  multidimensional assessment of hydro-ecological condition of water and bottom sediments by hydro-chemical, hydro-biological and radiation indicators;

-  orientation of field research towards a further assessment of trans-boundary contamination;

-  inviting highly qualified experts from institutions representing various ministries and departments to participate in the field work and laboratory analysis.

The weather conditions were not favorable for the field work. It was rather cold and windy for the season. The last ten days of the expedition were rainy. The precipitation level was average for this time of the year. The river runoff was formed, for the most part, at the expense of underground water. Contaminants from agricultural lands and urban territories reached the water bodies under observation. The velocity of water flow was higher than the average. Thus, the field research data are representative enough for the preliminary evaluation of the total impact of both point and dispersed contamination sources, as well as for the comparative assessment of the contamination levels along the whole river length, including the trans-boundary cross-sections.

The list of measured indicators (see Table 1) corresponded to the initially suggested one. As compared to the 2000 expedition, the biota (pike and roach) was studied for the content of total beta-activity, Sr-90 and Cs-137, and water samples were analyzed for radioactivity.

Table 1. List of measured indicators

Some indicators (flow velocity and water runoff, temperature, clarity and turbidity, рН, dissolved oxygen) were measured at the sampling points, the rest of them - in the corresponding laboratories.

Water sampling points, as a rule, were selected alongside the selection of cross-sections for hydrometric measurements. Bottom sediment samples as well as water samples for the further hydro-biological and radiation laboratory analysis were mainly obtained some meters upstream of the cross-sections chosen for hydrometrical measurements.

The flow velocity and water runoffs were measured at 18 cross-sections. Water samples to be studied for hydro-chemical and hydro-biological indicators were taken from 24 cross-sections (23 as initially planned, and 1 additional cross-section at the Prostyr’ river), bottom sediment samples were taken from 15 cross-sections, biota samples – from 5 cross-sections, water and bottom sediment samples to be studied for radioactivity – from 10 cross-sections. Brief descriptions of the observed cross-sections are presented in Table 2 below. The cross-sections are numbered top-down from the Dnipro river source to its tributaries, the Prypiat river and its tributaries, which seems convenient for the further display of the expedition results.

Table 2. Main characteristics of the studied cross-sections of water flows in the Dnipro River Basin

In order to ensure the compatibility of the expedition results concerning water quality in the Dnipro Basin obtained in the water drainage areas of Belarus, Russia and Ukraine, hydrometric measurements and water and bottom sediment sampling were carried out on the same Prypiat tributaries and at the Dnipro trans-boundary cross-sections. The time of water running from an observed cross-section in the territory of Ukraine (Belarus) to the cross-section in the territory of Belarus (Ukraine) along the same water body, as well as the time of water running from an observed cross-section in the territory of Russia to the corresponding cross-section on the Dnipro, Sozh and Iput’ rivers in Belarus were taken into account where possible. The dates of measurement taking at the trans-boundary cross-sections are presented in Table 3, which shows that it was only for the trans-boundary cross-sections along the Dnipro river-bed (Komarin – edge of the Kyiv Water Reservoir) that the measurements were not adjusted to the time of water running, due to some logistical difficulties. However, given the insignificant precipitation level during the period of measurement taking, the time difference hardly affected the compatibility of the observation results.

Table 3. Water velocity at the transboundary cross-sections

UA- Ukraine, RB –Republic of Belorus, RF- Russian Federation

Table 4.  Dates of hydrometric measurement and sampling at the trans-boundary cross sections of Belarus, Ukraine and Russia

HYDROLOGY

The methodology of measuring water runoffs, hydro-chemical, hydro-biological and radiation indicators was described in detail in the complete report. The measurement results are presented below.

Water velocity and cross-section area were measured at 20 cross-sections (including an additional one on the Prostyr’ river, the village of Pare). The calculated data on water runoffs based on these measurements as well as water runoffs (computed by the correlation of water drainage areas) at 4 cross-sections (the Dnipro upstream of the city of Mogiliov, Dnipro downstream of the village of Rechitsa, Prypiat’ downstream the town of Mozyr’, Dnipro downstream the town of Komarin) are given in Table 5. The data on water runoffs at the trans-boundary cross-sections (see Table 6) correlate well with the similar data obtained by the Ukrainian and Russian expeditions.

The comparison of the observation results with the 2000 expedition data testifies that during the spring expedition of 2001 water runoffs at all cross-sections exceeded water runoffs in October 2000, with the only exception of the Svisloch river where water runoffs were lower than in the previous year, mostly due to the lower discharge of the Viley river water into the Svisloch basin.

Table 5. Results of hydrometric measurements in the Dnipro River Basin

Table 6. Water velocity and runoffs at the trans-boundary cross-sections

HYDROCHEMISTRY

Hydro-chemical indicators of water quality were measured at 23 cross-sections. For each cross-section, 33 indicators were registered, of which 10 – heavy metals in both suspended and dissolved forms. Summarized characteristics of the surface water quality of the Dnipro, Prypiat’ and their tributaries by hydro-chemical indicators are given in Tables 7 and 8 below.

Table 7.  Maximum allowable concentrations (MAC) of contaminants in surface water of the Dnipro River Basin

Table 8. Water contamination index (WCI)