2011 Issue №1(7)

This paper focuses on the impact of certain factors on the contemporary distribution of natural (226Ra, 232Th, 40К) and anthropogenic (137Cs, 60Co) radionuclides in the sediments of the Baltic Sea. The results of the study suggest that the distribution of 137Cs is determined by the content of hydromica of silty-clay and clay grain-size fractions, while radiocaesium is mainly accumulated by silty fractions. The accumulation of 226Ra by bottom sediments is mainly determined by the pH geochemical barrier at the water-seafloor boundary. The accumulation of 232Th occurs mainly in clayey fractions of the sediment. The distribution and accumulation of 40K is predominantly determined by the ratio of potassium contained in hydromica minerals. Significant 60Co activity was registered only in a few samples.

This article analyses characteristics of 25 rivers of the Gulf of Finland basin where the monitoring of the streamflow chemical composition was performed. The authors consider the dynamics of biogenic element content in the streamflow, the relation of the drainage areas to certain landscapes, the share of agricultural lands and tillage in the drainage areas, the forest-land percentage, a rural population density, and the forest age and type.

It is the first time pockmark-like structures have been detected in the south-eastern part of the Gulf of Finland with the help of a side-scan sonar and a profile recorder. The analysis of the distribution of microcomponents in the bottom sediment indicates that the pockmark area is located in the geochemical barrier border zone where the reducing medium of the incoming mineralized solution meets the highly oxidizing sea water medium. The hydrodynamic and geochemical processes in the pockmark zone create focal areas of anomalous microenvironment and affect the composition and development of benthos.

This article examines the current state of the groundwater system monitoring in the Novgorod region. The groundwater monitoring observations serve as the basis for prediction assessment of water resources. The efficiency of water resource management largely depends on the comprehensiveness and reliability of information on the groundwater condition.The existing groundwater monitoring system has proven to be incapable of fully implementing its functions. It requires a fundamental reorganization and further development at the contemporary scientific and technical level, since groundwater resource management is impossible without a quantitative forecast of groundwater condition and properties.From the perspective of rational Nature management, the leading ecological function of underground hydrosphere is carried out by fresh underground waters. Rational Nature management underlies the sustainable development of the Northwest region, which is economically viable for the European territory of the country.