¶ Jupyter notebooks
GFM offers a set of freely-accessible Jupyter notebooks available at the EODC's GFM GitHub. The notebooks provide a wide range of methods to find, accessing, and work with data from GFM's full archive. The currently available notebooks and their scopes are summarised in the table below.
| download_gfm_python.ipynb | how to query the GFM STAC collection using the Python library pystac_client and download the data using built-in Python libraries as well as utilizing the command line tool stac-asset |
| gfm_maximum_flood_extent_dask.ipynb | how to use the EODC Dask |
| gfm_dask_objectstorage.ipynb | how to remotely process data on the EODC cluster using Dask and save the result in a cloud object store |
| gfm_filter.ipynb | : how to refine the query against the GFM STAC catalogue using the filter STAC API extension |
| gfm_maximum_flood_extent_local.ipynb | how to find data using STAC, load it into a xarray object, and calculate a result |
| gfm_maximum_flood_extent_simple_plot.ipynb | how STAC can be used to find GFM data (ensemble_flood_extent) and derive the maximum flood extent from it |
| gfm_maximum_flood_extent_stac.ipynb | how STAC can be used to find GFM Observed Flood Extent data and derive the maximum flood extent from it |
| gfm_plot_flood_scene.ipynb | how to plot a part of a flooded GFM scene using an OpenStreetMap basemap as background |
| gfm_rfm_evaluation.ipynb | how to use the new GFM STAC service to derive the maximum flood extent for a flood event, extract the corresponding forecast product from the EFAS Rapid Flood Mapping layer and perform a simple evaluation |
¶ EODC STAC Catalogue Browser
EODC STAC Catalogue browser is available at
All required scenes is stored in the EODC Catalogue and through this browser desired catalog with the requested data can be opened. The latest data are shown on the right side of the screen.
If only specific scene from the catalog is needed, it can be searched using a filter: to do this, the desired catalog must be opened. By using the Show Filters button, data can be filtered temporally or spatially.
Under Temporal Extent you can select the desired time period, and under Spatial Extent you can choose the desired area.
Once the user has defined the desired parameters, the system will also allow the selection of the number of the results that will be displayed in each page (by default, this is set to 12).
By pressing Submit the user will let the system perform the query and the results will be shown right below the query form
When the user clicks on one of the retrieved scene, the system will display all the assets stored on the catalogue as in the figure below
By expanding each item, the user will presented all the options offered by the system for that specific product output (Download, Copy URL, Show on Map) including the intermediate products (e.g., the flood extent separately retrieved by each GFM algorithm), and its relevant metadata.
¶ Using STAC on QGIS
To open and display the data, QGIS is used. QGIS is an open-source geographic information system and can be downloaded from the following link: https://www.qgis.org/en/site/forusers/download.html
After successfully installing and opening QGIS the user needs to install a plugin. To do this, open the overview of all plugins via the tab Plugins > Manage and Install Plugins.
A new window opens and the STAC API Browser plugin is searched for via the search line and then the user must press Install Plugin. Once the plugin has been installed, the window can be closed.
The user then creates a new connection via Connections -> New. The name can be chosen as desired and the URL is: https://stac.eodc.eu/api/v1. Use Test Connection to ensure that the connection works and click on OK to create the connection.
To display the GFM catalogs, the user has to:
- type Global Flood Monitoring in the Filter collection textbox
- click on the Fetch collections button
- click on Search
The system will the display the list of available assets consistently with the query. The user can:
- click on View assets to decide to display the data on the dashboard or download the item
- click on Select footprint and the Add the selected footprint to visualise the data on the dashboard
¶ Further documentation on STAC Catalogues
- STAC specification: https://stacspec.org/en
- Reading Data from STAC API by Microsoft Planetary Computer. In general, there is good material to understand STAC: https://planetarycomputer.microsoft.com/docs/quickstarts/reading-stac/
- STAC Browser by "radiantearth". There you can add any STAC API URL (e.g. from CDSE, Google Earth Engine, etc.) and visualize respective STAC catalogs/items: https://radiantearth.github.io/stac-browser/#/
- EODC STAC API URL: https://stac.eodc.eu/api/v1
- EODC STAC Browser. EODC's instance of STAC Browser https://services.eodc.eu/browser/#/v1/
- EODC Knowledgebase: https://docs.eodc.eu/
- EODC Portal - new entrypoint for EODC services. Have a look at the "Explorer", which is another implementation for visualizing STAC catalogs/items: https://portal.services.eodc.eu/