Radioactivity Dynamics in River System
ＱDo high concentrations of radioactive cesium continue to be deposited on riverbeds? 【Deposition of sediment in riverbeds】
ＡContinuous deposition of sediment containing radioactive cesium are limited to flood plains containing vegetation. The radioactive cesium concentration in sediment in such regions is tending to decrease.
● The following tendencies were observed for the Ukedo River, Fukushima Prefecture.
- Flood channel where water reaches only at high water-level periods e.g. typhoon :
There are some places where radioactive cesium is easily deposited. But such places are limited.
- Place where water reaches several times a year :
Deposition and erosion of cesium are repeating. The deposited amount of cesium is typically low.
- Place that are easily flooded :
Radioactive cesium is scarcely deposited.
※ Similar tendency was observed for other river systems in eastern Fukushima Prefecture (Hamadori District)
- In what kinds of land use is radioactive cesium deposited? How much is deposited?
- Do high concentrations of radioactive cesium continue to be deposited on riverbeds? 【137Cs concentration where sediment continuously deposit】
- Where is radioactive cesium deposited in forests, and how much? How do the locations and amounts change over time?
- Cs released to the environment by the forest fire?