Flow visualization is an important tool for understanding and presenting complex data sets, especially when it comes to tracking the movement of quantities over time or from one point to another. One popular type of flow visualization is the Sankey diagram, which uses a series of interconnected nodes and flow arrows to depict the flow of data or resources.

In this article, we will explore the concept of Sankey chart creation, the different types of Sankey diagrams, and some real-world applications of this powerful visualization tool.

Sankey Chart Creation

Creating a Sankey chart involves several steps, from preparing the data to designing the layout and styling the components. The main elements of a Sankey chart are input/output sources (nodes), flow amounts (arrows), and labels.

Here’s an overview of the key steps when creating a Sankey chart:

1. Define Your Categories: Start by identifying the main categories or dimensions for your chart. For example, in an energy usage chart, you might categorize different energy sources or use types. Assign these categories with unique IDs.

2. Gather Quantitative Data: Collect the specific data for each category. This is usually in the form of quantities or measures that you want to visualize as flows between the categories.

3. Establish Sources and Sinks: In a Sankey diagram, sources are the starting points of flows, while sinks are the final points. For instance, oil drilling could be a source for a petroleum chart, and refining can be considered the sink. Determine which nodes function as sources and which as sinks.

4. Set Flow Amounts: Assign the quantities for each connection between sources and sinks. These quantities are visualized using arrows, the width of which provides a clear indication of the flow’s magnitude.

5. Create the Network: Arrange the nodes and draw flows from the sources to the sinks. You can use tools like Gephi, Tableau, Microsoft PowerBI, or even software like D3.js for more customization.

6. Customize and Style: In your chosen tool, you can adjust colors, widths of the flows, labels, and even add tooltips to provide additional information to the viewer.

Types of Sankey Diagrams

Sankey diagrams come in various formats, allowing you to adapt them to your specific needs:

• Parallel Sankey Diagrams: Great for highlighting small changes in flow quantities between categories. They are particularly effective when comparing the flows in a similar dataset over time.

• Diverging Sankey Diagrams: Useful for depicting the opposite side of flows. Dashed lines connect opposite flows, providing a clear visual distinction for contrasting quantities.

• Horizontal and Vertical Sankey Diagrams: These offer more flexibility in layout choices, which can improve readability when dealing with many nodes and a smaller screen.

Applications of Sankey Charts

Sankey diagrams find applications in a wide range of fields, from economic analysis to ecological studies. Below are a few examples:

• Economic Flows: Illustrating the flow of money or goods between different sectors, countries, or firms can provide insights into economic structures and dependencies.

• Energy Management: Analyzing energy consumption and generation across various sources like solar, wind, coal, hydro, and nuclear can help in optimizing energy distribution and conservation efforts.

• Data Flow Networks: In software engineering, visualizing data flow in complex processes or APIs can offer deeper understanding of system architecture.

• Urban Planning: Tracking the distribution of resources like traffic, energy consumption, or people movement in cities can inform infrastructure planning and resource allocation.

Conclusion

Sankey diagrams are an incredibly useful tool for creating intuitive visual representations of flow movements, whether they are data flows, material flows, financial flows, or more. By carefully designing them, presenting key data clearly, and emphasizing relevant insights, you can provide stakeholders with valuable information that can drive decisions and improve overall understanding.

If you’re working with data that has substantial flow relationships — linking concepts, connections, or movement — consider leveraging the flexibility and visual power of Sankey diagrams to enhance communication and analysis.

Are Sankey diagrams something you use frequently in your work or projects? Share your experiences and thoughts about this visualization method below!

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.