Long-term monitoring of the ~(137)Cs activity in suspended sediment transported by the Homerka stream, Polish Flysch Carpathians

摘要

The work reported was undertaken in the Homerka instrumented catchment in the Polish Flysch Carpathians. The ~(137)Cs activity of suspended sediment has been documented since 1984 using bulk samples of suspended sediment collected from the main gauging station and occasionally from tributaries during periods of flood discharge. The ~(l34)Cs content of the suspended sediment samples was also measured after the Chernobyl accident. Attention focuses on both the longer-term trends in radiocaesium activity and the shorter-term variations in the ~(137)Cs content of suspended sediment during flood events. The longer-term variations in the ~(134)Cs and ~(137)Cs activity of suspended sediment is shown to reflect the interaction of fallout inputs, radiocaesium storage and remobilisation and radioactive decay, whereas the short-term variability is seen to be controlled by the complex interaction of sediment sources, catchment contributing areas and the sediment delivery dynamics.