2019年秋の大会

講演情報

一般セッション

VII. 保健物理と環境科学 » VII. 保健物理と環境科学

[1D15-20] 環境放射能・モニタリング3

2019年9月11日(水) 16:25 〜 18:00 D会場 (共通教育棟 1F D12)

座長:町田 昌彦(JAEA)

16:25 〜 16:40

[1D15] Investigation on distribution of radioactive substances in Fukushima

(11)Spatial variation in the transport and deposition of radiocesium through the tree canopy via branchflow and stemflow

*Zul Hilmi Saidin1, Yuichi Onda1, Hiroaki Kato1, Momo Kurihara1, Slim Mtibaa 1, Kazuki Nanko2, Delphis F. Levia3 (1. Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Japan, 2. Department of Disaster Prevention, Meteorology and Hydrology, Forestry and Forest Products Research Institute, Tsukuba, Japan, 3. Departments of Geography, University of Delaware, Newark, Delaware, USA)

キーワード:Leachable radiocesium, Stable isotopes, Branchflow, Stemflow, Cedar stand, Oak stand, Bark water storage capacity

This study seeks to better understand the spatial variation in the transport and deposition of radiocesium through the tree canopy via branchflow and stemflow in the aftermath of the Fukushima Dai-ichi Nuclear Power Plant accident. Working in both a coniferous forest (Cryptomeria japonica, young Japanese cedar stands) and a mixed deciduous broadleaved forest (Quercus serrata, Japanese oak stands), we investigated the fate of radiocesium transported by branchflow from upper and lower portions of canopy and deposited by stemflow at trunk basal area. The results showed leachable radiocesium was greater for branchflow that received washoff from the dead foliage than the branchflow receiving radiocesium inputs from mixed and younger foliage. For the tree trunk, radiocesium leached more in stemflow from the lower part as compared to the upper part, possibly due to the increased residence time of stemflow on the lower reaches of the trunk. Further work should examine the effect of bark water capacity and its relationship with the 137Cs vertical distribution and isotopic composition of each tree stands.