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Water Observations from Space (WOfS)

Contributed by CEOS SEO/AMA

WOfS is an automated water mapping algorithm created by Geoscience Australia. Surface water is detected in satellite images and for each location the number of occurrences is summed through time. The result is a percentage value of the number of times water was observed at the location.

 

The colouring of the summary layer indicates how often water was observed. Possible floods appear in the low values (red to yellow colours), while consistent water bodies such as lakes and dams have high values (blue to purple colours).

More information.

Explore the Application

View the Notebook and sample outputs here.

Want to use the example Notebook on your own Data Cube and data? 

Download the Notebook from GitHub here and run it on your own Cube in a Box installation.

 

Tutorial

The video above provides a run through of the Notebook, with the steps listed here:

  1. All DCAL Notebooks begin by specifying a location, time window, and product of interest.

  2. The extents and products are examined and selected in the first 5 cells of the notebook, with user options available in the 2nd and 4th cells, marked by "# CHANGE HERE >>>>>>>>>>>>>>>>>>".

  3. Any values within the bounds detailed in the 3rd cell will work, and it is suggested to keep the region and time period small. The resulting area is shown in red in cell 5.

  4. You can click on the map to query the coordinates under the cursor.

  5. In cell 6, you load a region of the Data Cube using the selected extents, products and measurements. The resulting data are summarised in cell 7.

  6. Clouds are masked out in cell 8.

  7. WOfS classification occurs in cells 9-11, and display options can be customised in cell 12.

  8. Statistics showing the percentage of water classified pixels in the extent are calculated and visualised in the remaining cells.

  9. Finally, the result can be exported as a GeoTIFF file for download.