Transport and redistribution of radiocesium in Fukushima fallout through rivers

福島における河川を介した放射性セシウムの輸送, 再分配

谷口 圭輔*; 恩田 裕一*; Smith, H. G.*; Blake, W.*; 吉村 和也  ; 山敷 庸亮*; 倉元 隆之*; 斎藤 公明  

Taniguchi, Keisuke*; Onda, Yuichi*; Smith, H. G.*; Blake, W.*; Yoshimura, Kazuya; Yamashiki, Yosuke*; Kuramoto, Takayuki*; Saito, Kimiaki

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident released the largest quantity of radiocesium into the environment since Chernobyl. Here, we show for the first time, how redistribution of radiocesium by river and watershed-scale hydrological processes in Fukushima is driving localized decline in terrestrial dose rates in populated areas. The rate of Fukushima recovery greatly exceeds initial post-disaster expectations and indicates that landscape-scale recovery from such large contamination events is highly dependent on local hydrological and land use controls.