Sankey charts are a type of data visualization that helps to illustrate the flow of quantities between different variables. They are commonly used to display the distribution of resources, such as energy, money, or people, and are particularly useful when the emphasis is on the proportions of the flow.

In this article, we’ll explore the basics of creating and understanding Sankey charts, as well as their diverse applications, to help you harness the power of data in a visually intuitive way.

What Are Sankey Charts?

Sankey charts are named after Captain Matthew Henry Phineas Riall Sankey, who first introduced the concept in 1898 to visualize the energy efficiency of his employer, the James Walker Company, by depicting the flow of energy as moving along the thickness of arrows. This innovative use of visual metaphor allowed audiences to easily understand the complex data around energy distribution and consumption.

Key Components of Sankey Charts:

1. Nodes (Endpoints): These are typically represented as rectangular or circular shapes and represent the start or end of a flow.
2. Arrows (Edges/Flows): These show the material flow. The width of the arrow is proportional to the amount of flow represented, making it easy to see which flows are larger than others.
3. Labels and Legends: These provide context, such as the name of a company, type of material, or a financial category.

How to Create a Sankey Chart:

Creating a Sankey chart involves several steps, and the process can vary slightly depending on the software tool used (e.g., Tableau, Microsoft Power BI, or Python libraries like Plotly and networkx).

1. Gather Data: Collect the data that you wish to visualize, including the source, destination, and flow values for each link.
2. Prepare the Data: Organize your data in a format that your chosen tool can utilize. This typically includes multiple columns for source, target, and the value of the flow.
3. Use a Suitable Tool: Select a software tool that suits your needs and data format. Tools like Tableau allow you to drag and drop fields and automatically generate the chart based on your settings.
4. Customize the Visualization: Adjust settings and aesthetics of your Sankey chart, such as color schemes, arrow shapes, and node labels, to enhance readability and engagement.
5. Analyze and Iterate: Review the chart and make any necessary adjustments to better communicate your intended message or to clarify the data flow for the audience.

Applications of Sankey Charts:

1. Energy Consumption: Sankey charts are incredibly useful for visualizing energy usage and distribution within systems, showing how much energy is converted, lost, or used for specific purposes.
2. Business Processes: They illustrate the flow of resources in a business process, revealing bottlenecks, inefficiencies, and areas for improvement.
3. Economic Data: To show the flow of goods, labor, or capital between regions or sectors, helping in understanding economic interdependencies and trade dynamics.
4. Environmental Studies: Mapping the flow of water, pollutants, or other resources to analyze ecosystems and their interconnections in a geographical area.
5. Human Resources: Visualizing talent flow within a company, including hiring, promotion, and attrition, to identify areas for organizational growth or improvement.

Conclusion: Simplifying Data Flow with Sankey Charts

Sankey charts are a powerful tool for visualizing the flow of quantities between variables, making complex data more accessible and understandable. Whether analyzing energy systems, optimizing business processes, or studying environmental pathways, these charts provide a clear picture of the movement and distribution of resources. By simplifying data flow, Sankey charts empower us to make informed decisions based on a comprehensive understanding of the quantitative relationships between variables.

As you explore the creation and utilization of Sankey charts, remember to keep your audience in mind, ensuring the design is intuitive and the information is easily digestible. This will maximize the impact of your data visualization, leading to more effective communication and decision-making.

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.