Sankey charts, also colloquially referred to as stream graphs, are a unique and visually engaging tool used to illustrate complex systems’ flows. From illustrating electricity distribution to depicting information flow on the web, these diagrams are a powerful method for conveying the intricacies of complex processes in a concise and easily digestible format. In this comprehensive guide, we delve into the rich history of Sankey charts, their diverse applications, and essential best practices to ensure they are effectively utilized in data visualization.
### The Evolution of Sankey Charts
The origins of Sankey diagrams are rooted in the industrial revolution. In the 19th century, engineer and physicist William Playfair was instrumental in their development. His first known usage was to demonstrate the energy usage in railway systems. Since then, Sankey diagrams have become a staple in engineering, environmental management, and various other areas.
The core concept of a Sankey chart revolves around showing the magnitude of material or energy flowing through a process as an width of a stream. The wider the stream, the greater the flow.
### Uses of Sankey Charts
Sankey diagrams have become a go-to visualization in numerous fields, including:
– Energy conversion
– Environmental flows
– Inventory management
– Data transfer
– Production and processing logistics
In the following examples, we’ll spotlight the application of Sankey charts in these areas:
– **Energy Conversion** tracks the journey of energy from one form to another, indicating where the energy is lost or converted.
– **Environmental Flows** depict the pathways that matter takes through ecosystems, such as water or carbon flows.
– **Inventory Management** provides a visual representation of the flow of materials through a supply chain.
– **Data Transfer** demonstrates data exchange within a computer system or information network.
– **Logistics and Production** shows the efficiency of a production process by evaluating each step’s utilization of resources.
### Best Practices for Creating Sankey Charts
Sankey charts can become overwhelming if not crafted with precision. Here are some essential best practices for designing Sankey diagrams:
– **Balance the Width of Streams**: Vary the widths to reflect the magnitude of the flow accurately. Pay close attention to the areas where there are concentration changes within the flows.
– **Use Clear Labels**: Label the process stages and the stream flows to ensure that users understand the chart at a glance.
– **Minimize the Number of Streams per Unit**:
– Splitting the diagram can help if the flow is complex and hard to follow.
– Use separate diagrams to break down a large, intricate process.
– **Keep Streams Simple**:
– Avoid making streams too intricate or complicated by splitting them into several components.
– Use a consistent shape and style for all streams.
– **Consider the Color Scheme**:
– Use colors to convey the type of material or energy being depicted.
– Ensure that the color scheme enhances readability without overshadowing the data.
– **Use Interactive Features Wisely**:
– Incorporate interaction such as hover information or clickable elements to provide more context.
– Be cautious to not overdo it with interactions that could clutter the diagram.
– **Scale Your Chart Appropriately**:
– Sankey charts excel at illustrating larger flows. However, if you’re dealing with smaller values, use smaller diagrams or normalize the scale to maintain clarity.
### Conclusion
Sankey charts are much more than just a tool for engineers or scientists; they are versatile tools for any visual storyteller. Understanding their history, mastering their applications, and following these best practices will equip you to create Sankey diagrams that not only inform but truly inspire. Whether you’re analyzing material flows or showcasing complex processes, don’t underestimate the power of stream graphs to convey your message effectively and engagingly.
