Radiosesium migration, effluence path to water system, and mechanizum of transfer to rice in Fukushima

2015 Fiscal Year Final Research Report

• Project/Area Number: 25660188
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Rural environmental engineering/Planning
• Research Institution: The University of Tokyo
• Principal Investigator: Sho Shiozawa 東京大学, 農学生命科学研究科, 教授 (80134154)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 放射性セシウム / ため池 / 土壌への固定 / 底質のセシウム濃度

Outline of Final Research Achievements

In Fukushima there are Radiosecium (Cs) concentration hot spot, in some ponds, rivers in city, and Abukuma river. This research confirmed that the source of high concentration Cs from where Cs flowed out was not forest but city (asphaltic pavement and roof of buildings), by measuring sediment concentration（Fsed ；Bq/m2）in agricultural ponds and fallout concentration （Ffall ；Bq/m2）on the pond, and comparing the ratio Fsed /Ffall among three ponds of different land cover of those catchment. As the results Fsed /Ffall<1 for two ponds whose catchments are forest, indicating inflow Cs to the pond had been less than outflow Cs, however, Fsed /Ffall=4.8 for a pond whose catchments is mostly asphaltic pavement and building roof, indicating that large inflow of Cs (outflow from the catchment) had occurred.

Free Research Field

農地環境工学