[H-CG26] 福島第一原子力発電事故後の地域復興で科学者が今後取り組むこと

[HCG26-P09] Radiocesium transport on the hillslope of a backyard mountain

*登尾 浩助¹、砂川 優樹¹、本多 隆太¹、高木 悠輝¹、溝口 勝²、西村 拓² (1.明治大学、2.東京大学)

キーワード：土壌、水文学、コロイド

The radiocesium (Cs) fallout from the Fukushima Dai-ichi Nuclear Power Plant was scraped off from the surface layer on a hillslope of a backyard mountain in Iitate Village, Fukushima Prefecture. Since the fallout radiocesium was removed from the soil surface within a 20 m range from houses, we continued to monitor changes in Cs concentration at the surface layer from the foothill to the Cs-remaining part along the hillslope. Just after the Cs-removing process, Cs concentration on the whole slope was similar from the foothill to the uphill. Radiocesium transport on the hillslope of a backyard mountain seemed to increase during big rainfall events. With time elapsed, Cs concentration seemed to increase in the middle and upper hillslopes. Interestingly, Cs concentration in the Cs-remaining part increased with time, meaning that Cs was transported from the further upper part of the hillslope. Long-term monitoring on the hillslope and vertical transport to the deeper soil layers should be needed.