How to Use the Indonesia Rainfall Analysis Tool

About the Tool
This tool enables users to view satellite rainfall data and rainfall anomalies over Indonesia. The tool uses Climate Prediction Center Morphing Technique (CMORPH) data, from 2003 to the present. The data are updated every dekad (approximately every 10 days). This tool enables users to:

This tool can be helpful in understanding recent local rainfall conditions in particular locations in Indonesia.

Rainfall and Fire Activity in Indonesia
While this information about rainfall in Indonesia can serve a variety of purposes, this tool was originally designed to assist stakeholders in Central Kalimantan, Indonesia, and neighboring provinces to assess the likelihood of high or low fire activity in an upcoming season. Research conducted by IRI in partnership with CARE Indonesia and Bogor Agriculture University suggests that there is a close correlation between satellite rainfall data and fire hotspot activity in the peatland areas of the Kalimantan region. In particular, rainfall during the dry season from June to October is critical in determining fire activity, whether rainfall conditions in a particular location suggest a more- or less-intense-than-average fire season.

Therefore, if a user wishes to assess the likelihood of severe fires in a particular district, this tool can be used to create a graph of rainfall patterns in that district from 2003 to the present. The tool automatically calculates periods of anomalies (when rainfall is above or below average), and illustrates these through graphs.

For further information about the relationship between fire activity and satellite rainfall data, or if you have questions about how to interpret the data in this tool, please contact Pietro Ceccato (pceccato@iri.columbia.edu).

How to Use this Tool
The instructions below explain how to produce maps and create specific time series.

Interacting with the map
Creating time series analyses

Interacting with the map
The map first displays precipitation estimates from the most recent dekad, but it is also meant to be a dynamic tool. Users may use the map viewer to:

Display data for a different date
The dekad for which data are currently displayed on the map is shown to the lower left of the map. To display data from a different time period:
  1. Change the date in the text box above the map using the same format as the date already shown. You must enter date ranges as dekads. For each month, there are three dekads: days 1-10, days 11-20, and day 21 to the last day of the month. For example, in April the dekads would be entered as: 1-10 April 2008, 11-20 April 2008, and 21-30 April 2008.
  2. Click the Redraw button to the left of the map (top of the three buttons).
Note that to the right of the date text box, there is a button that allows you to display the dekad immediately prior to the one currently being viewed (and if you are not viewing the most recent dekad, it will also display a button for the dekad after).

Animate data from multiple dekads
The map will display any number of dekads in animation. However, the time necessary to load the animation will increase with the number of time steps included in the selection.

  1. In the date text box above the map, enter the starting and ending dekads of the time period over which you would like to animate the data, separated by "to" (e.g., "11-20 Dec 2002 to 21-31 Dec 2003"). Or, if you enter "Sep 2004", for example, you will see an animation of the three dekads in that month. If you enter "Sep 2004 to Aug 2005", you will see an animation of all the dekads from the beginning of September 2004 through the end of August 2005.
  2. Click the "Redraw" button to the left of the map (top of the three buttons).

Overlay adminstrative boundaries
Any combination of the available overlay maps may be displayed.

  1. Using the "Optional Overlay Maps" table located on the right side of the map, select the overlays that you would like to display. For example, if you select "districts" you will see district boundaries on the map.
  2. Click the Redraw button to the left of the map (top of the three buttons).

Zoom map in/out
There are two ways to zoom the map to different regions; a click-and-drag zoom window and the latitude/longitude text boxes. Note that the map cannot display areas outside of the region first shown on the interface (i.e., 12.5°S - 9.5°N, 90°E - 155°E).

  • Click-and-drag zoom window
    1. Click and drag a window on the map over the region of interest. The map will automatically zoom to that region when the mouse button is released.
    2. You can return to the full domain of the map at any time by clicking the Zoom Out button to the left of the map (middle of the three buttons).
  • Specific lat/lon selection
    There are four lat/lon text boxes underneath and to the left of the map.
    1. Change the values in the lat/lon text boxes to the limits of the region you would like to display using the text format already shown.
    2. Click the Redraw button to the left of the map (top of the three buttons).
Creating time series analyses
Users may generate time series analyses of precipitation at any location on the map.

Generate time series analysis

  1. Using the "Time Series Region" table to the right of the map, select the size of the region over which you want the precipitation to be spatially averaged. For example, if you wish to view precipitation data that are spatially averaged over a district, click on "district boundary".
  2. Click on the map at the point of interest. The analysis will be based on the average of the data within the grid box of the size indicated in Step 1 closest to this point.
Custom modifications to time series graphs
After the time series analyses have been generated, the user has a few additional options to modify the presented plots.
  • Select specific lat/lon coordinate to analyze
    1. Select the size of the region to be included in the analysis from the pull-down menu.
    2. Enter the latitude and longitude of the point of interest.
    3. Click the "Generate new time series" button.

  • Modify graphs
    1. Click on any of the graphs to bring up an interactive viewer that will allow you to modify the aesthetics of the selected graph.
    2. Change the values in the text boxes to modify the temporal range of the graph and/or the limits of the vertical axis.
    3. Click the Redraw button to the left of the graph.

  • Download graphs in a variety of formats
    1. Click on the graph of interest to bring up the interactive viewer, if you have not already done so (see Modify graphs above).
    2. Select the desired download format (e.g., PostScript, JPEG, GIF, PNG) from the options available in the "Just the Figure Formats" line of the table. Static URLs for the selected image are also available in the Page Fomats line of the table and more information about these page formats can be found by clicking the "Help" button.

Please feel free to email us with any questions or comments.