Geospatial View Multilayer

Our objective is to develop a multilayer geospatial visualization. We utilize the coordinates of Seattle's elementary schools and their corresponding attendance zones as input data. Additionally, we aim to showcase the bike paths accessible for commuting to these schools.

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.

The data input is stored in the workflow area. We use a CSV reader to read the attendance areas, which are saved as polygons in the WKT format, to obtain the coordinates of the elementary schools in the lat/lon format. To get the required data for the bike lanes, all you need to do is execute the "Read Dataset" component.

The first step is to transform the input data to geometry data using the WKT to Geometry and the Lat/Lon to Geometry node. We also filter the elementary school using the available attendance areas.

To add a marker column for the map tooltip and colour coding, we include an "Object Type" column for each branch. This column will have values like "Bike Lane," "Elementary School," and "Elementary School Attendance Area." We add this column by using the Constant Value Column node.

To create a multilayer geospatial view, you must use the "Concatenate" node to merge the geometry data from the attendance area table, elementary school table, and bike lanes table. The visualization will follow the order of the input tables so that the attendance areas will be plotted first, followed by bike lane lines and the school points.

Next, we use the Geospatial View node to display the results. As you hover over the various coloured areas, points, and lines, you can view the elementary schools' names, attendance areas, and bike lanes.

After examining the map, you can respond to these inquiries:

- Which elementary schools do not have access to any bike lanes?
- Which school attendance areas are lacking in bike lanes?
- Which schools have the most favourable biking routes?

External resources

• Traffic Lanes
• Seattle Public Schools Sites 2022-2023
• Elementary School Attendance Areas 2022-2023