River flood following to a gigantic typhoon induces increase of dissolved radiocesium in estuarine and coastal waters of Fukushima

Abstract

Using samples collected in the lower Abukuma River before and after the passage of Typhoon Hagibis in 2019, changes in the concentration of dissolved radiocesium) desorbed from riverine suspended particles that had been introduced in seawater by the laboratory experiments and model calculations. The concentration of dissolved radiocesium increased immediately after the typhoon, and returned to the same level as before the typhoon in about two weeks after that due to the dilution effect of seawater with low-radiocesium. In this study, we were able to predict temporalchange of the concentration of dissolved radiocesium in coastal waters after floods caused by the heavy rain following to the typhoon.