Case of Juman Mountain Forest Fire in 2017
ＱHow much did the amount or the concentration of Cs released to river water by forest fire? How did them change by time?
ＡThe release rate of radioactive cesium was higher in the burned area than that previously observed. It is assumeed that the release rate becomes same level of the unburned area with the plant coverage recovering in burned area.
- JAEA has observed the release of radioactive cesium about a half year from 1 month after the extinguishment.
- In the result of the monitoring, the release rate of radioactive cesium was higher in the burned area than that previously observed because the plant coverage decreased in the burned area.
- For the reason above, it is considered that the release rate becomes same level of the unburned area with the plant coverage recovering in burned area.
Table 1 Other data of the release observation
|Upper area of Uda river||Japanese red pine, ceder, broad-leaved trees, Japanese cypress||0.086～1.1％
|錦織 et al., 2015|
|Kawamata Town||Japanese ceder||0.07％
|Yoshimura et al., 2015|
|Niizato et al.,2016|
|Broad-leaved trees (decontaminated)||0.84％
|渡辺et al., 2019|
- Does the concentration in river water change before and after forest fire? How did it change by time?
- Any method to evaluate damaged location by the forest fire?
- Do sediment with high radioactive cesium concentration continue to be deposited on river bottoms?
- Is there a continuous input of cesium contamination to rivers from forests?
- When it rains, does radioactive cesium flow out of forests with soil? 【137Cs flow from river basins and mountain slope】
- 錦織ほか（2015）, 林床被覆の違いが土壌侵食に伴う放射性セシウムの移動に及ぼす影響, 日本森林学会誌, 97, pp.63-69.
- Yoshimura, et al., (2015), Evaluation of Radiocaesium Wash-off by Soil Erosion from Various Land Uses using USLE Plots, Journal of Environmental Radioactivity, 139, pp.362-369.
- Niizato, et al. (2016), Input and output budgets of radiocesium concerning the forest floor in the mountain forest of Fukushima released from the TEPCO's Fukushima Dai-ichi nuclear power plant accident, Journal of Environmental Radioactivity, 161, 11-21.
- 渡辺ほか（2019）, 除染後の落葉広葉樹林林縁地における放射性セシウム流出量の経年変化”、第20回「環境放射能」研究会要旨集、P-23.
- 長尾ほか(2019), 福島における放射性セシウムの環境動態研究の現状（平成30年度版）, JAEA-Research 2019-002, 235p.