Contribution of particulate Cs from rivers to Cs concentrations in coastal sediment off Fukushima

鈴木 翔太郎*; 佐久間 一幸   ; 鶴田 忠彦  ; 松本 陽*; 天野 洋典*; 榎本 昌宏*; 守岡 良晃*; 神山 享一*; 高田 兵衛*

Suzuki, Shotaro*; Sakuma, Kazuyuki; Tsuruta, Tadahiko; Matsumoto, Akira*; Amano, Yosuke*; Enomoto, Masahiro*; Morioka, Yoshiaki*; Kamiyama, Kyoichi*; Takata, Hyoe*

To evaluate contribution of riverine particulate Cs input, we estimated Cs concentration coastal sediment (7-20 m depth) with particulate Cs flux of the total 13 rivers (Uda, Mano, Niida, Ohta, Odaka, Ukedo(+Takase), Maeda, Kuma, Tomioka, Ide, Kido, Natsui, Same) calculated by tank model for water discharge and empirical equations for suspended solids fluxes and Cs discharge between May 2011 and March 2020. Calculated particulate Cs flux from the river were ranged from 2.1110 to 497910 Bq/month. Estimated Cs concentration including particulate Cs via deposition kept concentration level more than minimum 0.351 Bq/kg-dry when initial Cs concentration, variation rate and deposition ratio were set 300 Bq/kg-dry, -95% and 0.1, respectively.