Flowing Data: Crafting Creative Communication with Sankey Charts

In the realm of data visualization, Sankey charts stand out for their ability to illustrate complex flows from one value to another, making them a powerful tool for creative communication of data. These flow diagrams, named after Mark Sankey, an engineer who used them to visualize steam flow in industrial machinery, have evolved into a versatile format for displaying the movement of materials, energy, and information in various contexts. If you’re ready to craft effective communication with Sankey charts, this guide will walk you through their creation and applications.

Understanding Sankey Charts

Sankey diagrams visually represent the sequence and scale of materials or energy flowing from one step in a process to another. They typically show the percentage contribution of each step, along with the cumulative flow through the process. The width of the arrows or lines usually indicates the quantity or flow rate of each element. The structure of a Sankey chart can vary, but it generally includes:

Sources, representing the starting points of the data flow.
Steps, showing the intermediate stages through which the data flows.
Destinations, indicating where the data ends up.
Transitions, represented by the lines, indicating the movement of data from one step to another.
Flow rates, often depicted by the width of the lines, showing how much data moves through each transition.

Creating Sankey Charts

Creating a Sankey chart involves two primary steps: data preparation and chart design. Here’s a basic guide to get you started:

1. Data Preparation

First, gather and organize your data. This typically involves identifying the different sources, steps, and destinations of your data flow. Ensure your data is in a format suitable for a Sankey chart, which usually means you’ll have at least three columns: the step or destination, the flow rate, and an optional type or category for further differentiation.

2. Designing the Chart

Once your data is ready, it’s time to design the chart. There are several software tools and programming languages you can use to create Sankey diagrams, including Excel, Python using libraries like Plotly or Matplotlib, and R using the ggalluvial package. Here are some tips for design:

Choose the Right Software: Select a tool that allows for customization and visualization of your data in an effective manner.
Plan Your Layout: Consider the flow of your data and the visual hierarchy. Arrows can be straight or curved, and their thickness should reflect the flow rate.
Use Colors Wisely: Color can help highlight different flows or categories, but ensure it’s not the only means of emphasis. Make sure your color scheme is consistent and accessible for non-color-blind viewers.
Label Clearly: Include labels for your sources, steps, and destinations. Make them readable without cluttering the chart.

Applications of Sankey Charts

Sankey charts are not limited to their original use in engineering; they’re widely applicable across many fields:

Environmental Science: Illustrating energy flows, waste management, and carbon footprints.
Economics: Showing the flow of money, or the distribution of income and wealth.
Social Science: Representing the flow of people through different stages, like education levels or employment sectors.
Information Technology: Visualizing data flow into and out of databases, or the processing of information within systems.

Conclusion: Crafting Creative Communication with Sankey Charts

Sankey charts are a fascinating tool for visualizing complex information flows. By understanding their structure, principles of design, and the data behind them, you can create compelling visual narratives. Whether in the realm of scientific research, business operations, or data journalism, Sankey charts offer a unique way to communicate intricate and multi-layered data in a clear and accessible manner. Take the time to craft these beautiful diagrams, and let the data tell its story to its audience.

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.