Flow Maps

Learn how to create flow maps for visualizing movement and connections between geographic locations.

Overview

Flow Maps display directed connections between geographic locations, showing the movement or flow of people, goods, information, or other phenomena. Lines connect origin and destination points, with line thickness often representing the volume or intensity of the flow.

Flow maps are essential for visualizing migration patterns, trade routes, transportation networks, communication flows, and other directional relationships between geographic areas. They excel at revealing patterns in movement data that might not be apparent in other visualization types.

Setup

After inserting a map, navigate to the Map tab in the right panel. In the Setup section, you can assign basic properties to the map, which are detailed on the Maps overview page. Next, open the Map Type section and click on Flow Map.

Connecting to a Basemap

In the Basemap section under the Map tab, you can select an underlying basemap for your map element. The basemap is a map, stored in GeoJSON format, consisting of features (geographical shapes) such as countries, provinces, and electoral districts. In order to add a basemap to a map element, you must first add a basemap to your project. This can be done by selecting New Basemap in the Project tab. Clicking Find Basemap then opens a library of more than 600 basemaps to choose from.

Pro

If you are on the Pro plan, you can upload your own files (in GeoJSON format) to use as basemaps, by clicking New Basemap, then Upload Basemap.

Connecting to Datasets

In the Dataset section, you can select the dataset for your map element. For raster maps, your dataset should include spatial coordinates and the values to be displayed as a raster surface.

Pro

If you are on the Pro plan, you can upload your own files (in csv format) to use as datasets, by clicking New Dataset and then Upload Dataset.

For flow maps, your dataset should include:

  • Origin Latitude and Origin Longitude fields for the starting points
  • Destination Latitude and Destination Longitude fields for the ending points
  • A Flow Value field representing the volume or intensity of the flow

Connecting to Filters

You can establish connections to filter elements under the Map tab, in the Connections section, by making a selection under Filter.

Filter elements display values from a specified Filter Field, in the form of checkboxes, dropdown menu items, or (for numeric filtering) slider values. A given map can be connected to one or more filters, and the same filter can be connected to multiple maps or other elements.

Colors

In the Colors section under the Map tab, you can assign a Color Field from the selected dataset. This allows you to color-code flows based on categories or value ranges, adding another dimension of information to your visualization.

Flow Lines

In the Flow Lines section, you can configure properties related to the appearance of the flow connections:

  • Flow Value Field: Select the field that determines the thickness of each flow line
  • Maximum Line Width: Sets the line width when a flow value reaches the maximum
  • Minimum Line Width: Sets the minimum line width for the smallest flows
  • Line Style: Choose between straight lines, curved lines, or other styling options
  • Arrow Style: Configure arrow heads to show flow direction

Annotations

In the Annotations section under the Map tab, you can add annotations consisting of text and/or symbols to your map to provide additional context for the flow patterns.

Tooltips

Tooltips on flow maps can be enabled by selecting the Map tab, navigating to the Tooltip section, and selecting Display Tooltip. These will display information about each flow when users hover over the connecting lines.