Colorful Currents: Mastering the Art of the Sankey Diagram

Sankey diagrams, named after their inventor, English engineer and physicist William Playfair, have been an important tool in the field of data visualization for over two centuries. These intriguing charts are particularly useful for representing flow or quantities in complex systems, making them an invaluable asset in fields like engineering, environmental studies, and finance. In this article, we will explore the art of creating Sankey diagrams and understand their applications across various domains.

Understanding the Basics

What is a Sankey Diagram?

A Sankey diagram is a directional flowchart that depicts the quantity of materials, energy, or cost as it moves through a system. The arrows indicate the direction of flow, and the width of the arrows is proportional to the magnitude of the flow. Sankey diagrams are highly informative as they can show the efficiency of a process at a glance and highlight where energy and resources are being lost.

Key Characteristics

• Stream Lines: The main flow (stream) is shown in a continuous line, illustrating the direction and magnitude of the flow.
• Force Lines: These are small lines that show the overall direction of the forces influencing the flow.
• Sankey Law: The width of a stream line is proportional to the amount of flow, and adjacent stream lines are separated by a distance to represent the forces acting on the flow.
• Arrow Heads and Tails: Endpoints of stream lines have arrow heads and tails to depict the direction of flow.

Crafting Your Sankey Diagram

Choosing the Right Software

To create a Sankey diagram, you’ll need appropriate software. A variety of programs offer Sankey chart functions, ranging from simple spreadsheet software like Microsoft Excel to specialized tools like Sankey Diagrammer or TIBCO Spotfire. The choice depends on the complexity of the diagram and your familiarity with the software.

Steps to Create a Sankey Diagram

1. Define the System: Clearly define the elements and processes of your system.
2. Identify the Flows: Determine the quantities moving between these elements, including both inputs and outputs.
3. Select Stream Lines: Establish the overall direction of flow and create stream lines for each type of flowing material.
4. Determine Widths: Assign the appropriate widths to the stream lines based on the flow magnitudes.
5. Add Labels and Connections: Label the elements and flows, and ensure all connections are clear.
6. Color Code: Use a color scheme that is visually appealing and easy to follow. Common color use includes black or dark gray for background and contrasting colors for each flow type.
7. Fine-Tune: Review your Sankey diagram for accuracy in flow representation and layout. Adjust line thickness and spacing as necessary.

Applications of Sankey Diagrams

Environmental Engineering

Sankey diagrams are widely used in environmental engineering to represent energy flows in buildings, industrial processes, and entire ecosystems. This allows engineers to identify inefficiencies and areas where resources can be conserved.

Energy Management

In the energy sector, Sankey diagrams help visualize the efficiency of power generation from various sources like solar, wind, or nuclear, to transmission, and consumption.

Business and Finance

In business, these diagrams can display the flow of money, resources, or information within a company, providing insights into cost drivers, production bottlenecks, and resource allocation.

Urban Planning

Urban designers use Sankey diagrams to illustrate the flow of traffic, people, or goods within cities and to plan more efficient transportation networks.

Industrial Chemistry

Chemical engineers use Sankey diagrams to analyze the mass balance of reactants, products, and energy exchange in chemical processes, which can assist in optimization.

Education and Research

Sankey diagrams are also incorporated in educational materials and research to demonstrate concepts in physics and economics, making complex systems more understandable.

Conclusion

In summary, Sankey diagrams are a powerful tool for visualizing complex systems with a focus on quantity and flow. Whether you are a data scientist, engineer, environmentalist, or business professional, learning to create Sankey diagrams can greatly enhance your ability to convey the core processes within your chosen field. The colorful current flow of Sankey diagrams provides a clear and concise representation that can lead to improved efficiency, optimization, and decision-making in numerous contexts. As you master the art of creating Sankey diagrams, remember to keep simplicity and clarity in mind, ensuring that your diagrams serve as valuable insights into the systems they represent.

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.