Dynamics of radioactive cesium in coastal area linked with river discharge

Misono, Toshiharu   ; Tsuruta, Tadahiko  ; Shiribiki, Takehiko; Nakanishi, Takahiro   ; Nagao, Seiya*; Ochiai, Shinya*; Sanada, Yukihisa   

For understanding future radioactive Cs dynamics and its distribution in the coastal area of Fukushima Prefecture, it is important to evaluate the supply of radioactive Cs from river discharge. Especially particulate radioactive Cs supplied in floods might have a significant impact on the coastal area. However, there are few studies on the dynamics of particulate radioactive Cs at the coastal area linked with rivers at the flood event. As a result of measuring the Cs concentration of the sinking particles collected by the sediment trap, at the observation point installed in front of the river, the Cs concentration collected immediately after the typhoon Bualoi (October 25th) was about higher than before the typhoon. However, the Cs concentration of the sinking particles collected two days after the typhoon was almost the same as before the typhoon. The impact of rivers on coastal areas during torrential rain stuck is extremely limited.