Flow Map

A flow map is a cartographic technique that uses lines or arrows drawn between origin and destination points to represent the volume and direction of movement. The width of each line is typically scaled to the quantity being moved—such as tons of cargo, number of migrants, or data packets—making it easy to identify dominant routes and minor connections simultaneously. Flow maps have a long history dating back to Charles Joseph Minard’s famous 1869 map of Napoleon’s Russian campaign. Modern flow maps are used for visualizing airline routes, commuter patterns, supply chain logistics, telecommunications traffic, and wildlife migration corridors. Edge bundling techniques group nearby flows together to reduce visual clutter on maps with many connections. Creating effective flow maps requires careful design choices about line curvature, color encoding, and aggregation level. Interactive versions allow users to filter by origin, destination, or time period. Libraries like kepler.glKepler.glKepler.gl is an open-source geospatial analysis tool for large-scale data visualization. Developed by Uber, it provid..., D3.js, and Flowmap.blue provide specialized tools for building flow maps from tabular origin-destination data. GISGISGeographic Information Systems (GIS) enable users to analyze and visualize spatial data to uncover patterns, relation... platforms such as ArcGISArcGISArcGIS is a leading GIS platform offering tools for spatial analysis, mapping, and data visualization. It serves a wi... and QGISQGISQGIS is a user-friendly, open-source GIS platform that provides tools for geospatial data analysis, mapping, and inte... also support flow map generation through network analysisNetwork AnalysisNetwork analysis in GIS models and solves problems on linear networks such as roads, utilities, and waterways. It ena... extensions.