Geospatial Projection

Choosing the proper projection is critical for Geospatial Analysis. This workflow uses different CRS to show Washington state boundaries.

To use the workflow, download and run it on the KNIME Analytics Platform. For optimal performance using the Geospatial Analytics extension, make sure you are using version 4.7.4 or higher.

We have generated the Washington state boundary map using the US2020 TIGER Map to prove the above. To create your map, please see the Links section for the list of FIPS codes.

In this example, we've entered only the two-digit code for Washington State (53) and "state20" for the "TIGER/Line data type" option. This is because we're not interested in visualizing additional subdivisions such as counties or tracts.

Next, we have connected our Washington state geometry polygon to three different Projections nodes. We have used distinct Coordinate Reference Systems with each node: World Azimuthal, Web Mercator and Equal Earth projections.

The projection process involves converting the three-dimensional Earth into a two-dimensional map, which creates distortions explained in the video "Why all world maps are wrong", linked in the "External resources" section. For more information about this topic, please see the e-guide "A practitioner's guide to geospatial analytics: the no-code approach" in the "External resources" section.

Unfortunately, these distortions can negatively impact specific properties, such as the area, form, distance and direction.

We've made a specific component that contains three Geospatial View Static nodes which show various projections. This component lets you see how different projections affect the map of Washington State. By opening the view, you can observe the forms of the map along with a short description.

Please notice that the effect of projection can only be displayed using the Geospatial View Static since all other nodes reproject the data into the CRS of the underlying base map.

External resources

• A practitioner’s guide to geospatial analytics: the no-code approach
• KNIME Components Guide
• FIPS codes list
• Coordinate System Worldwide. To search for CRS codes
• Why all world maps are wrong - Video