| 研究課題/領域番号 |
18H03389
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| 研究機関 | 福島大学 |
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研究代表者 |
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| 研究分担者 |
高瀬 つぎ子 福島大学, 共生システム理工学類, 特任准教授 (10466641)
脇山 義史 福島大学, 環境放射能研究所, 准教授 (40594792)
塚田 祥文 福島大学, 環境放射能研究所, 教授 (50715498)
RAHMAN Ismail 福島大学, 環境放射能研究所, 准教授 (60773067)
高橋 隆行 福島大学, 共生システム理工学類, 教授 (70197151)
難波 謙二 福島大学, 共生システム理工学類, 教授 (70242162)
和田 敏裕 福島大学, 環境放射能研究所, 准教授 (90505562)
Zheleznyak Mark 福島大学, 環境放射能研究所, 特任教授 (90745712)
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| 研究期間 (年度) |
2018-04-01 – 2021-03-31
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| キーワード | Fukushima / Chernobyl / environment / contamination / radiocesium / fate and transport / rivers / lakes |
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| 研究実績の概要 |
The peculiarities in climate, geomorphology and radiocesium (r-Cs) speciation in the fallout were demonstrated to lead to differences in migration rates of r-Cs in the environment and rates of its natural attenuation. Wash-off from the slopes of contaminated catchments and river transport are key long-term pathways for radionuclide dispersal from contaminated areas after the Fukushima accident. The climate conditions for the Fukushima Prefecture of Japan are characterized by higher annual precipitation as compared with Chernobyl with maximum rainstorm events during typhoon season. Typhoons Hagibis in 2019 demonstrated the substantial redistribution of r-Cs on river watersheds and floodplains and in some cases natural self-decontamination occurred. Steep slopes of Fukushima catchments are conducive to higher erosion and higher particulate r-Cs wash-off. Irrigation ponds in Okuma and Futaba towns demonstrated persistent behavior of r-Cs similar to the closed lakes in Chernobyl, its concentration is decreasing slowly and showing regular seasonal variations: the r-Cs concentrations tend to grow in the summer and decrease in the winter. A methodology for reconstruction of radionuclide long-term dynamics in rivers and lakes was proposed and applied for bottom sediment cores collected in Ogaki Dam reservoir at Ukedo River, as well as in at Chernobyl Exclusion Zone. Reconstructed time dependences of particulate and dissolved r-Cs in these water bodies were in good agreement with monitoring data and simulations using the proposed semi-empirical “diffusional” model.
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| 現在までの達成度 (段落) |
令和2年度が最終年度であるため、記入しない。
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| 今後の研究の推進方策 |
令和2年度が最終年度であるため、記入しない。
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