Results of the Measurement of Depth Distribution of Radioactive Substances in Soil in the Model Area (around Yamakiya District of Kawamata Town) ( July 2013, October 2013 )
- The analysis results show radiation (Bq) per unit dry weight (kg) of soil or litter.
- In order to confirm the changing trend of the concentrations of radioactive substances in the forest, upland field and grass land, we conducted a subsequent scraper plate survey at the locations adjacent to the first survey, the second survey, and the third survey (June 2011 to March 2013) .
- Soil sampling was conducted from July 13 to July 19, 2013 as well as sampling at the rice paddy on October 9, 2013.
- Soil samplings using scraper plates were conducted for 5 mm (0.5 cm) intervals between depths of 0 and 5 cm, for 1.0 cm intervals between depths of 5 and 10 cm and for 5.0 cm intervals between depths of 10 and 20 cm. If the surface was covered with vegetation or dead grasses, these were also collected separately from the soil samples. The vegetation and dead grasses were defined as litter in the forest and as grass plant/dead grass in the upland field and grass land. Litter (layer of leaves, branches, fruit, tree barks and fallen trees that have been barely decomposed by soil organisms).
- Samples were first dried 24 hours in 110℃. The litter samples were then triturated by the mixer and were put in the U-8 container. The soil samples were directly put in the U-8 container. Radioactivity was measured by germanium semiconductor detector and derived amounts of radioactive cesium.
- Radioactivity concentrations and errors show decay-compensated values from measurement to sampling.
Results of the Measurement of Depth Distribution of Radioactive Substances in Soil in the Model Area (around Yamakiya District of Kawamata Town) ( From August 2012 to December 2012 )
- The analysis results show radiation (Bq) per unit weight (kg).
- In order to confirm the changing trend of the concentrations of radioactive substances in the forest, upland field and grass land, we conducted a subsequent scraper plate survey at the locations adjacent to the first survey (June - August, 2011) and the second survey (December, 2011 - January, 2012) .
- Soil samplings using scraper plates were conducted for 5 mm (0.5 cm) intervals between depths of 0 and 5 cm, for 1.0 cm intervals between depths of 5 and 10 cm and for 5.0 cm intervals between depths of 10 and 20 cm. If the surface was covered with vegetation or dead grasses, these were also collected separately from the soil samples. The vegetation and dead grasses were defined as litter in the forest and as grass plant/dead grass in the upland field and grass land. Litter (layer of leaves, branches, fruit, tree barks and fallen trees that have been barely decomposed by soil organisms).
- Samples were first dried 24 hours in 110℃. The litter samples were then triturated by the mixer and were put in the U-8 container. The soil samples were directly put in the U-8 container. Radioactivity was measured by germanium semiconductor detector and derived amounts of radioactive cesium.
- Radioactivity concentrations and errors show decay-compensated values from measurement to sampling.
Results of the Measurement of Depth Distribution of Radioactive Substances in Soil in the Model Area (around Yamakiya District of Kawamata Town) ( From December 2011 to January 2012 )
- The analysis results show radiation (Bq) per unit weight (kg).
- In order to confirm the changing trend of the concentrations of radioactive substances in the forest, upland field and grass land, we conducted a subsequent scraper plate survey to the scraper plate survey conducted in the summer, 2011 at locations nearby.
- The precipitation between the end of the first period of the first survey (summer, June - August, 2011) and the beginning of the second period (December, 2011 - January 2012) (i.e. between September, 2011 and December, 2011) was 611 mm, which was larger than that of summer season. The vegetation in the upland field, tobacco field, meadow and pasture was decreased in significant amounts. The remaining vegetation was dead plants. No cultivation took place during this period. Frozen top soil was found due to declining air temperature and increasing moisture content in the period between December, 2011 and January, 2012. In the tobacco field, top soil to a depth of 15 cm was found to be frozen. In the other areas, depths of 0 to 3 cm of top soil were found to be frozen. In the rice paddy, frozen top soil was not observed because survey period was earlier than that of other areas.
- Soil samplings using scraper plates were conducted for 5 mm (0.5 cm) intervals between depths of 0 and 5 cm, for 1.0 cm intervals between depths of 5 and 10 cm and for 5.0 cm intervals between depths of 10 and 20 cm. If the surface was covered with vegetation or dead grasses, these were also collected separately from the soil samples. The vegetation and dead grasses were defined as litter in the forest and as grass plant/dead grass in the upland field and grass land. Litter (layer of leaves, branches, fruit, tree barks and fallen trees that have been barely decomposed by soil organisms).
- Samples were first dried 24 hours in 110℃. The litter samples were then triturated by the mixer and were put in the U-8 container. The soil samples were directly put in the U-8 container. Radioactivity was measured by germanium semiconductor detector and derived amounts of radioactive cesium.
- Radioactivity concentrations and errors show decay-compensated values from measurement to sampling.
- "ND" in the column "Deposition" and "-" in the column "Error": The peak of relevant nuclide was not clearly detected or calculated deposition was equal to or below 0.0.
Results of the Measurement of Depth Distribution of Radioactive Substances in Soil in the Model Area (around Yamakiya District of Kawamata Town) ( From June 2011 to August 2011 )
- The analysis results show radiation (Bq) per unit weight (kg).
- In order to clarify the difference of depth distribution of radioactive substances in the soil due to differences in the natural environment, eight sampling points were chosen such as forests (young stand cedar, mature stand cedar and broad-leaf mixed forest), upland fields (tobacco fields, farmland), paddy field, grass land (meadow) and pasture in Kawamata Town County Date, Fukushima Prefecture.
- Soil samplings using scraper plates were conducted for 5 mm (0.5 cm) intervals between depths of 0 and 5 cm, for 1.0 cm intervals between depths of 5 and 10 cm and for 5.0 cm intervals between depths of 10 and 20 cm. If the surface was covered with vegetation or dead grasses, these were also collected separately from the soil samples. The vegetation and dead grasses were defined as litter. Litter (layer of leaves, branches, fruit, tree barks and fallen trees that have been barely decomposed by soil organisms).
- Samples were first dried 24 hours in 110℃. The litter samples were then triturated by the mixer and were put in the U-8 container. The soil samples were directly put in the U-8 container. Radioactivity was measured by germanium semiconductor detector and derived amounts of radioactive cesium.
- Radioactivity concentrations and errors show decay-compensated values from measurement to sampling.
- "ND" in the column "Deposition" and "-" in the column "Error": The peak of relevant nuclide was not clearly detected or calculated deposition was equal to or below 0.0.
