Gorbachova L. The factors, structure and dynamics of dissolved in water Caesium-137 removing with water run-off in Prypyat river basin

It is investigated the factors, conditions and dynamics of the dissolved in water Caesium-137 re-moving with water run-off in the transboundary Prypyat river basin. It is carried out analysis of the spatial and temporal radioactive contamination of the basin by Сaesium-137. The results of the annual water run-off study of the Prypyat river for period 1987-2002 is presented. The balance method of the estimation of the different water run-off feeding components of role in the dissolved in water Caesium-137 removing is developed. It is fulfilled the quantitative estimation of the average dissolved in water Caesium-137 activ-ity in the annual water run-off and in the components of the Prypyat river and it is determined the struc-ture and value of its removing with these components. It is detailed and improved the model of long-term dynamics of the specific Caesium-137 activity in the Prypyat river taking into account its feeding genesis. It is developed and realized the methodical basis for calculation andprognostic modelling the dissolved in water Сaesium-137 wash-out factors according to different feeding components. The results can be used by environmental protection authorities in order to plan and realize of ecology and rehabilitation meas-ures on the radioactive contaminated catchment areas.