Sankey charts are a type of flow diagram used to visualize the distribution and flow of data across different categories or stages in a system. They are often used to illustrate energy, material, or financial transactions, as well as data flows in computer systems and other complex processes. This article will explore the power of Sankey charts and how they can be utilized to create compelling visualizations that help us better understand and interpret data.

What are Sankey diagrams?

Sankey diagrams, named after their creator, Matthew Henry Phineas Riall Sankey, are flow diagrams that use arrows and colored bands to depict the movement of data. Each band represents a quantity, and its width is proportional to the flow of data between different entities or stages. This makes it easy to see which parts of the system are contributing the most data, as well as which flows are larger or smaller.

Key Features:

1. Flow Visualization:

   • Sankey diagrams excel at showing the flow of data between different categories or stages.
   • The thickness or width of the arrows and bands represent the volume or amount of data moving.

2. Category Differentiation:

   • The use of color codes allows for easy differentiation between different categories or entities.

3. Hierarchical and Time-Evolving Data:

   • Sankey diagrams can show data flow in a hierarchical structure, making it suitable for nested data flows.
   • Temporal data can be visualized by updating the flow over time, effectively comparing different periods.

Applications:

• Energy Flow:
  • Energy consumption and production can be shown across different sources and uses, revealing the distribution of energy usage or consumption.
• Financial Flows:
  • Financial transactions between accounts or countries can be clearly visualized, highlighting the largest transfers or net inflows/outflows.
• Computer System Data:
  • Data flow within software applications, databases, or website traffic can be illustrated to understand performance bottlenecks or optimize resource allocation.
• Waste and Recycling:
  • Tracking materials like plastic, paper, or electronics through the recycling process.
• Transportation:
  • Routes and flows of goods movement in logistics, showing the most efficient or common shipping paths.

Tools for creating Sankey charts

Software Options

1. Gephi:

   • An open-source tool that offers a suite of network analysis and visualization techniques, including Sankey diagrams. It’s user-friendly for those with less technical skill.

2. Tableau:

   • A popular data visualization software that includes features to create Sankey diagrams. It offers a WYSIWYG (What You See Is What You Get) interface for quick and responsive visualizations.

3. Python Libraries:

   • Plotly:
     • A powerful library for interactive visualizations that supports Sankey diagrams with ease, allowing for the creation of web-based dashboards.
   • NetworkX:
     • Primarily used for network analysis, this library can generate graphs suitable for Sankey diagrams once you have the appropriate data fed into it.
   • SankeyPy:
     • An easy-to-use library specific for Sankey diagrams in Python, simplifying the creation process for those who prefer coding their visualizations.

Step-by-Step Guide to Creating Sankey Charts

Data Preparation:

1. Gather and clean the data needed: This includes identifying the sources and targets, determining the flow or transaction volumes for each, and any relevant categories or stages in the process.
2. Prepare data in a format suitable for the chosen tool (Excel, CSV, JSON, etc.).

Tool Selection:

Choose the most suitable tool based on your specific requirements and comfort level with technical or design processes.

Data Import:

Import the data into the selected tool according to its specific instructions.

Design Setup:

1. Arrange the data into categories, sources, and targets.
2. Define color-coding to differentiate between categories or stages.
3. Adjust size and shape settings as needed.
4. Add labels for clarity, including source and target names, category names, and volumes.

Final Details:

1. Add text and labels to explain or clarify specific details in the chart, such as key insights, totals, or specific transaction descriptions.
2. Adjust the layout and formatting as needed, fine-tuning the visual elements for clarity and aesthetics.
3. Test the dashboard or web interface if creating a dynamic visualization, ensuring navigation, interactivity, and responsiveness meet your needs.

Publication and Sharing:

1. Export the chart or dashboard as an image or interactive web component, depending on the tool used and desired output format.
2. Share the visual through websites, emails, platforms, or presentations, leveraging its insights to communicate effectively with your audience.

Conclusion

Sankey diagrams are a powerful tool for visualizing complex data flows in a way that is both intuitive and impactful. By providing a clear picture of the movement, distribution, and magnitude of data across different categories or stages, these charts enable us to make more informed decisions, optimize systems, and enhance overall understanding. Whether you’re creating Sankey diagrams for energy systems, financial transactions, or computer networks, leveraging the right tools and techniques can help you unleash their full potential.

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.