Sankey charts, also known as Sankey diagrams or flow charts, are a type of data visualization that is specifically designed to show the flow of quantities. They are particularly useful for visualizing processes, such as energy use, data processing, or economic transactions.
Introduction to Sankey Charts
Sankey charts were initially developed for visualizing the flow of electricity in power systems by mathematician John V. Atanasoff in 1931. They have since become an essential tool for analysts, engineers, and data scientists across various industries due to their ability to clearly communicate complex flows of data, information, or resources.
Components of a Sankey Chart
-
Nodes: These represent the starting and ending points of the flows. In the context of energy usage, nodes could represent sources (coal, wind, etc.) and sinks (residential, industrial).
-
Arrows: These connect the nodes and are wide at the source and narrow at the destination, allowing the viewer to easily understand which way the flow is going and how much of the flow is present at each step.
-
Colors: Often used to differentiate between various types of flows (e.g., heat, electricity, water).
-
Labels: Provide context and detail about what the flow represents (e.g., source node labeled as “Solar Energy”).
Creating Sankey Charts
Creating a Sankey chart involves several steps, depending on the tools you use:
-
Data Collection: Gather all the necessary data on the flows you wish to visualize. This could be from databases, surveys, reports, or other sources.
-
Data Preparation: Format your data to include source, target, and flow quantities. This might involve summarizing data, merging datasets, or calculating totals based on the nodes and links.
-
Tool Selection: Choose a tool or software that supports Sankey chart creation. Popular options include Tableau, Microsoft Power BI, Python libraries like
sane, and R libraries likeggplot2. -
Chart Building: Input your data into the chosen tool and use its features to create the nodes, connections, and flow widths. Adjust settings for colors, labels, and legends to enhance readability and aesthetics.
-
Review and Iterate: Fine-tune the chart to ensure clarity, balance, and effectiveness in communication. This might involve adjusting the layout, scale, or adding more detailed labels.
Applications of Sankey Charts
Sankey charts are versatile and can be applied across various sectors:
- Energy Sector: Analyzing the distribution of electricity, gas, and other energy sources.
- Environmental Science: Tracking the flow of resources or pollutants like CO2 emissions.
- Economic Analysis: Representing trade flows between countries or the movement of goods within an economy.
- Healthcare: Modeling the flow of patients through different stages of treatment in a hospital.
- Marketing and Sales: Visualizing customer journeys and sales funnels.
Best Practices
- Simplicity: Avoid cluttering the chart with too many flows, which can make it confusing. Focus on key flows that are most important or representative of the data.
- Proportional Widths: Ensure that the width of arrows accurately reflects the volume of flow. This helps in quickly understanding the significance of different flows.
- Consistent Scaling: Use consistent scaling across axes when plotting flows from various sources or destinations.
- Visual Hierarchy: Prioritize the display of flows that have more impact or represent larger quantities.
Conclusion
Sankey charts offer a powerful visualization tool for showing complex flows of data, information, or resources. By understanding their components, how to create them, and their applications, professionals from various domains can effectively communicate intricate processes and trends, making data more accessible and understandable to stakeholders.
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.
