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Forms and dynamics of technogenic radionuclides in the intrasoil flow in forest ecosystemsстатья
- Авторы: Shcheglov A.I., Klyashtorin A.I., Agapkina G.I., Mamikhin S.V., Tsvetnova O.B.
- Сборник: Radionuclide transport dynamics in freshwater resources. Radionuclide transport in freshwater systems: A synthesis of the results of the CRP
- Глава в коллективной монографии
- Год издания: 2002
- Место издания: IAEA, Vienna
- Первая страница: 41
- Последняя страница: 76
- Аннотация: Forest biota is of the key factors affecting the migration rates of 90Sr and 137Cs, and their possible transfer to ground water. Annual rates of the radionuclide uptake and return to the soil have a considerable effect on the radionuclide migration from the root-abundant soil layer to the ground water. The effect of soil absorbing complex and biological cycling on their migration is not as manifested as for 137Cs and 90Sr, and relative influx of plutonium to the ground water is more intensive compared to other radionuclides. Annual radiocaesium influx to the ground water is estimated as 0.03–0.05% of total deposition. The deposition of radiostrontium in the 30-km exclusion zone varies from 50 to 70% of 137Cs deposition. It may be assumed that at least 0.1% of total deposition of 137Cs and 90Sr in the hydromorphic areas comes annually to the ground water. In the automorphic areas, average annual rate of radionuclides replacement from forest litter to the mineral soil layers is about 1.9–3.7%. The corresponding figure for hydromorphic forest environments is about 7%. The radionuclide content in mineral soil horizons increases monotonously with time. Annual increment of 137Cs in the 5-cm mineral soil layer is about 4% in hydromorphic area and 3% in automorphic area. The corresponding rates for the 5–10-cm layer are 1 and 0.5%, respectively. Annual involvement of 137Cs and 90Sr into the biological cycle is much higher than their outflux from the biogeocenosis (both vertical and lateral). The large scale lateral redistribution of the radionuclides in the system of adjacent, geochemically joint landscapes does not exceed 1% per year for 137Cs, and is likely to be somewhat higher for 90Sr. The intensity of radionuclide redistribution at the scale of meso- and micro-topography (meters and tens of meters) may reach 10% per year.
- Добавил в систему: Цветнова Ольга Борисовна