Sankey charts have gained immense popularity among data analysts, data scientists, and marketers due to their ability to visually represent complex flow data in a clear and concise manner. Originating from the work of Scottish engineer Matthew Henry Phineas Riall in 1830, Sankey charts have come a long way from displaying steam flows across British industrial networks to various applications in different industries, making it invaluable in data storytelling.

In this article, we will delve into the intricacies of creating Sankey charts, the principles that differentiate them from other flow-charting techniques, as well as provide examples of their application across different industries. By the end of this guide, you will have comprehensive information on utilizing Sankey charts to effectively communicate your findings and insights.

Creating Sankey Charts: Principles and Techniques

1. Defining Sankey Charts

A Sankey chart is a type of flow diagram that illustrates the movement of data, quantity, or energy from one category to another, often used in contexts such as economics, energy use, and material flow analysis. Unlike standard bar or pie charts, Sankey charts emphasize the magnitude of flow between nodes by using the width of the transitions or “arrows” as a visual representation.

2. Key Elements of a Sankey Chart

Before you embark on creating a Sankey chart, it’s crucial to know the key elements that make up these visual representations:

• Nodes: These are the sources or destinations of the flow, often depicted as rectangles, circles, or other shapes.
• Arrows / Links / Bands: These represent the flow between nodes, with the width denoting the volume or quantity of the flow.
• Labels: Adding labels to nodes and arrows explains the specific data being represented, making the chart easier to understand.

3. Key Steps in Creating a Sankey Chart

i. Gather Data

The first step is to ensure you have the necessary data to create your Sankey chart, which involves identifying the source, destination, and volume of flow for each category you intend to show in your visualization.

ii. Prepare the Data

Organize the data in a format that matches the requirements of the Sankey chart library you’re using (e.g., Pandas DataFrame or SQL query output). Make sure each row contains details about the source, destination, and amount of flow between them.

iii. Choose a Visualization Tool

Select a robust visualization tool that supports Sankey charts. Popular choices include:

- **D3.js**: Great for web-based charts supporting both 2D and 3D charts.
- **Plotly**: Easy to use with many customization options for both web and offline applications.
- **Power BI**: Ideal for integrating Sankey charts with other business intelligence data sources.

iv. Customize Your Chart

Adjust the color, size, and appearance of your nodes, arrows, and labels to differentiate between different categories and highlight important data points.

v. Optimize for Clarity

Ensure that the layout and orientation make sense, minimizing visual clutter and emphasizing key insights. Consider sorting, grouping, or filtering data to provide a clearer depiction of the flow.

vi. Publish and Share

Finally, export your Sankey chart in the preferred format (e.g., PNG, SVG) and present it to your stakeholders. Don’t forget to include an explanation in the chart’s title or legend to convey the significance of your data.

Applications of Sankey Charts

Sankey charts are versatile and find applications in various industries:

1. Energy Flows

Sankey charts are commonly used to illustrate energy consumption and generation across different sources and end-use sectors, giving stakeholders a clear perspective on energy distribution and potential improvements.

2. Economic Flows

In economics, Sankey charts help visualize trade flows between countries, showing the exchange patterns of goods, services, and investments.

3. Logistics and Supply Chain Analysis

Sankey diagrams are invaluable in mapping logistics networks, tracking inventory, and optimizing the flow of goods between suppliers, manufacturers, and consumers.

4. Internet Traffic Analysis

Network engineers use Sankey charts to illustrate traffic flow on the internet, showing data transmission between various geographical locations and service providers.

5. Health Care and Epidemiology

Sankey charts provide insight into disease transmission or treatment pathways, highlighting the flow of patients through different health care processes or disease stages.

Conclusion

Sankey charts possess an undeniable power to convey complex flow data in an accessible and informative manner, making them an essential tool in the arsenal of data analysts, data scientists, and marketers. By understanding the principles of chart creation and recognizing their diverse applications, professionals can effectively communicate their findings, identify trends, and uncover valuable insights. As visualization tools continue to evolve, harnessing the unique capabilities of Sankey charts offers unparalleled potential in enhancing data storytelling and decision-making processes across various industries.

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.