Sankey diagrams, named after an English engineer Henry D. Sankey who first popularized them, are a powerful way of visualizing flows between nodes and their sizes. They provide an excellent visual representation of how flows transition from one point to the other, making them perfect for showing how energy, resources, or data moves around systems where multiple pathways are involved. Over the years, sankey charts have caught on in various fields like physics, economics, and now data science, thanks to their unique ability to express complex data stories in intuitive ways.

Creation of Sankey Charts: A Step-by-Step Guide

1. Data Preparation

Start by collecting your data. A classic sankey diagram requires at least three pieces of information:
1. Nodes: These are the points in your diagram. Each represents a distinct entity like cities, companies, or energy sources.
2. Directed Edges (Segments): Representing the connections between nodes. Each edge has a “capacity,” which indicates the amount transported or received.
3. Flow Values: Associated with each edge, indicating the scale, often visualized using color, size, or opacity.

For example, if your data involves showing the flow of goods between different cities, nodes would represent cities, and edges would represent trading relationships with flow values indicating the amount of goods moved.

2. Choosing the Right Software or Tool

While you can design sankey diagrams manually in Illustrator or Photoshop, several software tools are now available that simplify the process. Notable options include:
– Tableau
– Gephi
– D3.js (for more complex, custom designs)
– SankeyMaker
– Sankey Diagram by Microsoft SQL Server (for those with a SQL Server setup)

3. Creating the Layout

Using the tool of your choice, you’ll define nodes and set up edges between them based on your data. Most software provides an interface where you can manually place nodes, draw edges, and assign values or properties like colors and widths.

4. Designing for Clarity and Impact

Remember that simplicity is key. A well-labeled diagram with minimal visual clutter ensures the message is clear. Tools like SankeyMaker provide templates and design features to easily adjust elements such as:
– Node Placement: To keep flows aligned and visually organized.
– Edge Widths: To accurately represent flow values.
– Color Schemes: Adding significance to your data for easier interpretation, often used to highlight different types of flows or over time.

5. Review and Enhance

Finally, review the diagram’s comprehensibility. Ensure each element is meaningful within the overall data story. Tools often provide features to easily adjust elements, making it quick to tweak and perfect your chart’s clarity.

Applications of Sankey Charts

Sankey charts are widely applicable in many fields due to their unique power in visual storytelling:

1. Energy and Power Systems

Demonstrating the source, allocation, and consumption of energy across different sectors like nuclear, renewable, thermal, and waste can be challenging without a sankey diagram. They clearly show the flow and proportions involved, making the data accessible even to those without extensive knowledge.

2. Economic Flows

In economics, sankey charts are invaluable for visualizing trade flows, employment sectors, or financial transactions. They help in understanding the dynamics of supply and demand, showing how resources move through the economy.

3. Data Flow Analysis

In the realm of data science, they were initially used to visualize data transmission between databases or application components within IT systems. As datasets grow in complexity, sankey diagrams become a critical tool for understanding data pipelines and processes.

4. Physical Flow Analysis

In engineering disciplines, particularly in physics, sankey diagrams are used to represent the flow of heat, fluids, or processes. They aid in understanding how systems operate and optimize resources.

Conclusion

Sankey charts are indispensable tools for visualizing flows, not just because they are aesthetically pleasing but because they provide insights that tabular data or static graphs might not. From understanding complex economic networks to tracking energy consumption in cities, sankey diagrams offer a streamlined method to communicate substantial information clearly and effectively. Whether you’re a data analyst, an economist, an engineer, or simply someone who needs to communicate complex information in a digestible way, sankey diagrams provide a powerful visual representation of data in action.

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.