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
  • 1The notification of the the database site is displayed.
  • 2The renewal history of the database site is displayed.
  • 3It's better to visit a database site, and seen contents are displayed.
  • 4When contents are chosen, I transfer in the screen of contents which indicates measured data of chosen contents.
  • 5When the description button is pressed, the description of each contents is displayed.
  • 6The site description of the the database site is displayed.
header image
  • 7Please 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
  • 8The data I'd like to indicate on the map is measured, please choose time and target for measurement and press a measured data indication button.

Please refer to 9-12 about each item inside the tree on the page left side of the contents page.

contents page tree image
  • 9Please choose measurement time of the data you'd like to indicate on the map by a pulldown dated or a slider.
  • 10Please choose target for measurement of the data you'd like to indicate on the map by a pulldown.
  • 11Choose 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 pressing over the blue letter on the list and a number.
  • 12The data I'd like to indicate on the map is measured, please choose time and target for measurement and press a measured data view button.
contents page map image
  • 13Displayed data is displayed by measured data on the map by a point or the mesh shape.
contents page ballon image
  • 14When displayed data is pressed, 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
  • 15When Select Square button is pressed, it's possible to choose measured data in the area where a mouse was operated on the map together.
  • 16When Release Select button is pressed, the choice state of the measured data chosen on the map can be released completely.


contents page make link image
  • 17Please refer to this for data display.
contents page print map image
  • 18When Print button is pressed, I transfer in the page which prints the contents which are being displayed at present.
  • 19It's possible to do PDF output, PNG output and print by a printer by a designated paper size on the print page.
contents page make link image
  • 20When Make Link button is pressed, Uniform Resource Locator of the contents which are being displayed at present is displayed.
contents page download image
  • 21When Download button is pressed, it's possible to download even at most 200,000 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
  • 22When you'd like to change the kind of maps shown to a contents page, please press Change Map button.
contents page change map image 2
  • 23The 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
  • 24When you'd like to show geographical information to a contents page, please press View GIS button.
contents page geographic image 2
  • 25Geographical 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 9 kinds, Elevation, Vegetation, Land-use, Accumulated Snow, Soil, Bathymetric, Sediment, Population and Landmark(Junior High School, Elementary School) according to the use and indicate it.
    When selecting 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.
contents page geographic image 2
  • 26It is a display image of a landmark (school information).
    When you select the landmark, the school name will be displayed in a pop-up.

3. Database contents page(Map function)


The contents page has functions such as displaying graticule on the displayed map and moving the map by entering latitude and longitude.

contents page change map image 1
  • 27Press Graticule button if you want to display the graticule on the map.
contents page change map image 2
  • 28Graticule is displayed on the map.
    By enlarging / reducing the map, the range of graticule can be switched.


contents page geographic image 1
  • 29Press Control button if you want to enter the latitude and longitude and move the map or if you want to know the center coordinates of the currently displayed map.
contents page geographic image 2
  • 30The center coordinates of the currently displayed map are displayed.
    Latitude and longitude values are automatically updated when you move the map.
    Also, if you enter the latitude and longitude and press "Move to this position", the map will move to the specified coordinates.
contents page geographic image 1
  • 31If you want to check the currently displayed part in a wide area, press Submap button to display the submap.
contents page geographic image 2
  • 32The current location is displayed in a wide area.
    When you move the map, the submap also moves.
    Also, if you move the red frame in the submap, the currently displayed map will also move.
contents page geographic image 1
  • 33If you want to search by place name or building name, you can search the map only in Japanese.
    This function is created using the Geographical Survey Institute API.Excessive access is restricted, so please refrain from using it for searching a large number of cases.
contents page geographic image 2
  • 34When you select a link in the search results, the marker will be plotted at the selected location.
contents page geographic image 1
  • 35※Tablet / smartphone only.
    Press Location button if you want to display your current location on the map.
contents page geographic image 1
  • 36If you allow the use of your current location, the marker of your current location will be plotted on the map.
    This is the display image of the iPad.

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 pressed, Time Change Graph or Depth Distribution Graph is displayed by measured data.
In the case of sea area data, the unit of 'Upper depth of sampling' and 'Lower depth of sampling' are not expressed in cm but in m.

view data page graph image
  • 1Measured data can indicate 6 spots of minute at the same time on the graph.
  • 2When X-Axis Logarithmic indication and Y-Axis Logarithmic indication are designated, a chart is displayed by the designated contents.
  • 3When Output PNG button in the graph is pressed, 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 Measured Data Table tab of a view data page is pressed, 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 pressed, the price which considered physical reduce is displayed about the date designated as right of a line of the price of the list.
In the case of sea area data, the unit of 'Upper depth of sampling' and 'Lower depth of sampling' are not expressed in cm but in m.

view data page measured data table image 1
  • 1Please press Measured Data Table tab.
  • 2Please input the date which would like to calculate physical reduce.
view data page measured data table image 2
  • 3The 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 Download tab of a view data page is pressed, 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
  • 1Please press Download tab.
  • 2When a button is pressed, it's possible to download the measured data which was changed to the pressed 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
  • 3The 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 pressing Search button from header, search page is displayed.
When a Keyword is input, and a Search button is pressed, 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 200,000 cases.

search page image 1
  • 1Please designate search condition and press Search button.

Please refer to 2-7 about each item of the search condition of a search page.

search page image 2
  • 2Please input the Keyword included in the measured data.
  • 3Please 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.
  • 4Please choose a period of measured data from a pulldown dated or a slider.
  • 5Please choose Sample classification of measured data from a pulldown.
  • 6Please 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.
  • 7If designation of search condition of 2-6 ends, please press a Search button and search.


search page image 3
  • 8I transfer in the screen of contents which was chosen from a search result when measured data was selected and View Map button was pressed, and chosen measured data is displayed on the map.
  • 9When CSV download button is pressed, it's possible to download a search result by the CSV file format.
    CSV file will be download by UTF-8 form.