What is "Database for Radioactive Substance Monitoring Data"?

Japan Atomic Energy Agency (JAEA) regularly collects and publishes via an online database* environmental monitoring data related to the TEPCO Fukushima Daiichi Nuclear Power Plant accident, published by various organizations including the Secretariat of the Nuclear Regulation Authority, Fukushima Prefecture, research organizations, and so on. Gathered data are converted into a common file format (CSV format) suitable for analyzing the spatial distributions and temporal changes of radioactive materials. Geographical data useful for this analysis, such as elevation, soil, vegetation, land-use and snow coverage data etc. are also published on the same website. Various maps and graphs showing distributions of radioactive materials are also available on the website to promote intuitive understanding for users

*The database aggregates environmental monitoring data such as air dose rates and radioactivity concentrations on the ground surface, in soil, seawater, marine sediments, river water, river sediments, groundwater and food for Fukushima and neighboring prefectures. Note that as JAEA updates the database at periodic intervals, data value difference might occur between values in the database and those published by original organizations, for instance, when an organization revises its data subsequent to its aggregation and registration in the JAEA database.

What does this Database provide?

  • Based on the results from radioactive substance surveys, the database displays distribution maps of radioactivity concentration or dose rate.
  • Based on the results from radioactive substance surveys, the database displays graphs of time change of radioactivity concentration or dose rate.
  • Download of survey results of radioactive substances is available with various file formats including CSV, SHP, and KML.

Recommended environment

  • Personal computer
    • Windows
    • Mac
    • Linux
  • Tablet
    • Android
    • iOS
  • SmartPhone
    • Android
    • iOS
  • Supported browsers
    • Apple Safari 14.0 Or later
    • Google Chrome 86 Or later
    • Google Chromium 86 Or later
    • Microsoft Edge 87 Or later
    • Mozilla Firefox 82 Or later

How to display measured data. Page Top

1. Database top page

The spatial dose rate and contents of concentration of radioactivity are displayed on the top page.

top page image
  • aThe renewal history of the database site is displayed.
  • bIt's better to visit a database site, and seen contents are displayed.
  • cWhen contents are chosen, I transfer in the screen of contents which indicates measured data of chosen contents.
  • dWhen the description button is clicked, the description of each contents is displayed.
header image
  • *1Please refer to this to search for measured data of the purpose using a checking function.

2. Database contents page


A tree is shown to the page left side and a Japanese map is shown to the page right side on the contents page.

contents page image
  • eThe data I'd like to indicate on the map is measured, please choose time and target for measurement and click a measured data indication button.

Please refer to *1-*5 about each item inside the tree on the page left side of the contents page.

contents page tree image
  • *1Please choose measurement time of the data you'd like to indicate on the map by a pulldown dated or a slider.
  • *2Please choose target for measurement of the data you'd like to indicate on the map by a pulldown.
  • *3Choose from a list, and please check on the data you'd like to indicate on the map.
    Further the explanation about its item is displayed by the data number's and the "i" registered with a follower of each item clicking over the blue letter on the list and a number.
  • *4The data I'd like to indicate on the map is measured, please choose time and target for measurement and click a measured data view button.
contents page map image
  • fDisplayed data is displayed by measured data on the map by a point or the mesh shape.
contents page ballon image
  • gWhen displayed data is clicked, details of measured data are displayed by a balloon.
    A mesh code, a base date, the measure and data classification of target for measurement are displayed in the balloon.
    When a base date is an area, chosen data shows that more than one measured data is included and is the reach of the base date not each data, but in the mesh.


contents page footer image


contents page select square image
  • hWhen a select square button is clicked, it's possible to choose measured data in the area where a mouse was operated on the map together.
  • iWhen a release select button is clicked, the choice state of the measured data chosen on the map can be released completely.


contents page make link image
  • jWhen a make link button is clicked, Uniform Resource Locator of the contents which are being displayed at present is displayed.
contents page print map image
  • kWhen a print button is clicked, I transfer in the page which prints the contents which are being displayed at present.
  • lIt's possible to do PDF output, PNG output and print by a printer by a designated paper size on the print page.
contents page download image
  • mWhen a download button is clicked, it's possible to download even at most 100,000 cases of measured data chosen on the map.

3. Database contents page(Ancillary information display)


It's possible to indicate a change in the map which is being displayed and geographical information on the map on the contents page.

contents page change map image 1
  • *1When you'd like to change the kind of maps shown to a contents page, please choose this.
contents page change map image 2
  • *2The map which is shown by a chosen map to a contents page is switched over.
    A Japanese map does early stage indication of a map, but it's possible to choose from 5 kinds, a Japanese map, a Pale color map, a Blank map, a Photo and English (English map) according to the use and change.


contents page geographic image 1
  • *3When you'd like to show geographical information to a contents page, please choose this.
contents page geographic image 2
  • *4Geographical information is displayed by chosen geographical information on the map of the contents page.
    Geographical information isn't displayed by early stage indication, but it's possible to choose from 5 kinds, Elevation, Vegetation, Land-use, Accumulated Snow and Soil according to the use and indicate it.
    When clicking Areas where Returning is Difficult(As of March.2021.), you indicate the present Areas where Returning is Difficult(As of March.2021.) by a slanted line of a blue frame on the map.

How to display graphs. Page Top

1. Database view data page(Time Change Graph・Depth Distribution Graph)

When the measured data displayed on the contents page is chosen and a Detail Data button is clicked, Time Change Graph or Depth Distribution Graph is displayed by measured data.

view data page graph image
  • nMeasured data can indicate 6 spots of minute at the same time on the graph.
  • oWhen X-Axis Logarithmic indication and Y-Axis Logarithmic indication are designated, a chart is displayed by the designated contents.
  • pWhen a Output PNG button in the graph is clicked, it's possible to download the graph which is being displayed at present by the PNG form.

How to confirm the details of measured data. Page Top

1.Database view data page(Measured Data Table)

When a Measured Data Table tab of a view data page is clicked, details of the measured data chosen on the screen of contents are displayed by a list.
When a date is designated as physical reduce in the list lower left and a calculate button is clicked, the price which considered physical reduce is displayed about the date designated as right of a line of the price of the list.

view data page measured data table image 1
  • qPlease click a Measured Data Table tab.
  • rPlease input the date which would like to calculate physical reduce.
view data page measured data table image 2
  • sThe price which considered physical reduce from the price of the measured data is displayed.
    ※Before March 11, 2011 on the system and, it's possible to designate it until the far future, but the calculation value of such setting doesn't make the sense because I calculate by the simple physical reduce system.

How to download measured data. Page Top

1.Database view data page(Download)

When a Download tab of a view data page is clicked, it's possible to download the measured data chosen on the screen of contents by the form of one of CSV, KML and SHP.

view data page download image
  • tPlease click a Download tab.
  • uWhen a button is clicked, it's possible to download the measured data which was changed to the clicked file format.
    CSV file will be download by UTF-8 form.

2.Unified Format

To make the comparative analysis between the different survey item easy, the CSV file which unified header was prepared.
The header composition is as follows.

CSV FILE Header image
  • vThe case when measured data is the spatial dose rate indicates "Height of Measurement(cm)" and the occasion of the measured data besides the spatial dose rate indicates "Upper depth of sampling(cm)" for the header item "Upper depth of sampling or Height of Measurement(cm)".

How to search for measured data of the purpose. Page Top

1.Database search page

When clicking a Search button from header, search page is displayed.
When a Keyword is input, and a Search button is clicked, the result for which I searched by a Keyword is displayed by search page.
But, please narrow search condition down and search because it isn't possible to do the search which exceeds 100,000 cases.

search page image 1
  • wPlease designate search condition and click a Search button.

Please refer to *1-*6 about each item of the search condition of a search page.

search page image 2
  • *1Please input the Keyword included in the measured data.
  • *2Please choose contents of measured data from a pulldown and check the measurement classification for which I'd like to search.
    The measurement classification by which measurement classification is everything in cases with no checks is included in a search target.
  • *3Please choose a period of measured data from a pulldown dated or a slider.
  • *4Please choose Sample classification of measured data from a pulldown.
  • *5Please designate the measurement location of the measured data.
    A measurement place can designate urban and rural prefectures, a city and a mesh code and search.
  • *6If designation of search condition of *1-*5 ends, please click a Search button and search.


search page image 3
  • xI transfer in the screen of contents which was chosen from a search result when measured data was clicked and View Map button was clicked, and chosen measured data is displayed on the map.
  • yWhen a CSV download button is clicked, it's possible to download a search result by the CSV file format.
    CSV file will be download by UTF-8 form.