Sankey charts offer a visually stunning way to represent complex data flows, with a history dating back to the 19th century when they were developed to model energy flows in factories. While traditional Sankey charts are often associated with industry and economics, these powerful visualization tools have found widespread application in a variety of fields, including data science, urban planning, and environmental science, to name a few. In this article, we’ll explore the basics of Sankey chart creation, their diverse applications, and tips on how to effectively use them to communicate complex data with elegance and clarity.

Understanding Sankey Charts

A Sankey chart is a type of flow diagram where the width of a link indicates the quantity of flow, hence the name “Sankey,” derived from its inventor, Captain Matthew Henry Phineas Riall Sankey. Developed to make the flow of manufactured goods legible, Sankey charts have evolved to illustrate a multitude of flows from information, data, and material flows to energy consumption and financial transactions.

Key Elements of a Sankey Chart

1. Nodes: These typically represent the start, end, and intermediate points of the flow.
2. Links: Also called flows, these connect the nodes, showing the direction and quantity of data moving from one node to another.
3. Widths: The width of each link corresponds to the volume or value of the flow it represents.
4. Colors and Legends: These are used to distinguish between different types of flows or to highlight specific data categories.

Creating Sankey Charts

Tools for Creation

Choosing the right tool depends on your specific needs, budget, and technical expertise. Popular tools include software such as:
– Tableau for those needing a user-friendly interface with powerful visualization capabilities.
– Python with libraries like Plotly or NetworkX, suitable for users comfortable with programming and customizability.
– Microsoft Power BI, which offers built-in Sankey chart features with a streamlined interface.

Best Practices in Design

• Simplicity: Keep the chart uncluttered by limiting the number of nodes and flows.
• Consistency: Use a consistent color palette to distinguish between categories.
• Accessibility: Ensure readability for all viewers, considering color blindness and high contrast.
• Interactive Elements: For detailed data views, consider implementing interactive elements like tooltips, filters, and drill-down capabilities.

Applications of Sankey Charts

1. Data Science: Illustrating data transformation processes like machine learning model predictions or data pipeline flows.
2. Environmental Science: Modeling energy consumption, material flow, or ecosystem interactions.
3. Business and Finance: Representing sales, supply chain, or financial transactions to highlight major impacts or efficiency bottlenecks.
4. Urban Planning: Depicting traffic flow, utility networks, or land use distribution to optimize urban development and infrastructure planning.
5. Healthcare: Analyzing patient flow through treatment processes, or disease transmission routes.

Conclusion

Sankey charts offer a visually elegant and informative way to present complex data flows. Whether you’re analyzing data in the lab, optimizing business operations, or planning city landscapes, these charts provide a compelling framework to communicate the intricate details of your data in a clear and engaging way. As you explore or create your own Sankey diagrams, remember to prioritize simplicity, clarity, and user experience to ensure your intended audience can easily grasp and appreciate the value of the information presented.

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.