Flow Visualization Made Easy: A Beginner’s Guide to Sankey Charts
Sankey charts are a powerful tool in data visualization, allowing us to understand and communicate the connections and flows within complex systems. These charts can represent a range of scenarios, from the energy used in a manufacturing process to the movement of traffic on a network of roads. The key feature of a Sankey chart is its ability to visually represent the transfer of quantities (such as energy, money, or materials) between different units or nodes through interconnected pipes or arrows. In this article, we will explore the creation and applications of Sankey charts, making this sophisticated tool easily accessible to beginners.
Understanding Sankey Charts
Sankey charts were first conceived by Sir William Thomson and his student P.R. Abney in the late 19th century. Named after T.S. Sankey, a steam engineer whose diagram for his energy-saving engine was one of the earliest examples, these charts have become a common tool in the data analyst’s repertoire.
Components of a Sankey Chart
A Sankey chart comprises three main elements:
1. Nodes: These are the points or categories where the flow starts and/or ends. Nodes represent the entities being connected, typically named and categorized.
2. Flows: These are the paths connecting the nodes, indicating the direction and quantity of flow or transfer between the entities.
3. Width: The width of the flow lines is proportionate to the quantity of flow, allowing viewers to interpret the magnitude of the movement easily.
Creating a Sankey Chart
Creating a Sankey chart involves several steps that can be streamlined using various data visualization tools. Here’s a basic guide using the online tool “sankeychart” and a simple dataset:
Tools for Sankey Chart Creation
- Online Tools: Sankeychart, Datawrapper, Tableau Public
- Coding Libraries: D3.js, Plotly.js, FusionCharts
- DIY Apps: Google Spreadsheets, Excel
1. Prepare Your Data
markdown
| Source | Flow | Destination | Quantity |
|--------------|------|-------------|----------|
| Material A | | Material B | 200 |
| Material A | | Material C | 150 |
| Material B | | Material D | 300 |
| Material C | | Material D | 250 |
2. Input Your DataSet into the Tool
- Sankeychart: Upload your dataset or create a new one with the provided schema.
- Datawrapper: Import your dataset, specifying the columns for source, destination, and quantity.
3. Customize the Chart
- Title and Labels: Adjust these to clearly define the context and relationships depicted.
- Colors: Use distinct colors for sources and destinations to make the chart visually appealing and easier to interpret.
- Layout: Choose the layout for your nodes (e.g., position them according to flow or statically).
4. Publish Your Chart
- Save and publish your chart to share with others or embed in a blog post, presentation, or report.
Applications of Sankey Charts
Energy Efficiency
Visualize the flow of energy within a manufacturing facility, showing efficiency levels in different parts of the process by comparing energy input with output, or by categorizing energy types (e.g., renewable vs. non-renewable).
Financial Flows
Map the flow of money in accounting and finance, showing the inflow and outflow at stages in a business process (e.g., sales to payment) and highlighting potential bottlenecks or inefficiencies.
Supply Chain Management
Analyze the movement of goods in a global supply chain, identifying bottlenecks, efficiency gains, or areas of leakage between stages (e.g., logistics, manufacturing, warehousing).
Technology Usage
Show the usage flow for web traffic, app usage, or service demand, between different platforms, devices, or user demographics, allowing optimization for UX and target marketing strategies.
Environmental Impact
Illustrate the movement of greenhouse gases or pollutants through various natural and industrial processes (e.g., fossil fuel combustion to CO2 emissions), emphasizing sources and sinks.
Conclusion
By mastering the basics of creating and interpreting Sankey charts, beginners can effectively communicate complex data flows in a clear, engaging, and visually impactful manner. Whether used to optimize processes, inform decision-making, or simply present data in a digestible format, Sankey charts provide a robust solution for visualizing connections and movement in diverse data contexts. With the right tools and an eye for design, even those beginning their journey in data visualization can harness the power of Sankey charts to enhance their understanding and that of their audiences.
SankeyMaster
SankeyMaster is your go-to tool for creating complex Sankey charts . Easily enter data and create Sankey charts that accurately reveal intricate data relationships.
