Sankey charts are a remarkable data visualization tool that serve as a window into the intricate web of energy or material flows within a system. Often mistaken for a work of abstract art, these diagrams, while visually complex, are powerful communication tools that simplify the study of transitional data. At first glance, they might appear challenging to interpret, but with a guiding hand through their complex branches, they reveal hidden patterns and trends that are often hidden from plain sight.
A Sankey chart is unique in that it maps the overall movement of flow items through a process by showing their quantity as they flow from one process to another. The width of the arrows in a Sankey chart often corresponds to the amount of product, energy, or information being transferred along them, creating a clear picture of flow intensity in a network or process.
In this post, we explore the origins, characteristics, and applications of Sankey diagrams to help you develop a deeper understanding of how they can unlock the potential of transitional data.
**Origins in Industrial Age**
Sankey diagrams trace their roots back to the 19th century, when they were initially developed by Irish engineer Matthew Sankey. They were created to show energy efficiencies within industrial processes, and have since adapted to depict the flow of multiple kinds of transitions, including information, material, and energy flows.
**Key Characteristics of a Sankey Chart**
– **Arrow Flow:** The main visual element of the Sankey chart is the flowing arrow, which illustrates the flow of materials, energy, or information.
– **Arrow Width:** The width of the arrows indicates the quantity of the flow item being transferred; wider arrows symbolize a higher flow rate.
– **Nodes:** Nodes represent the starting point and/or endpoint of flows and can be processes, regions, or categories.
– **Connection:** Connections show the flow from one process to another. The directionality of the arrows indicates the flow direction.
**Applications of Sankey Charts in Various Fields**
– **Energy Flow Analysis:** In renewable energy projects and environmental assessments, Sankey diagrams help visualize the energy usage and conversion efficiency.
– **Supply Chain Mapping:** Sankey charts can illustrate the flow of products or materials within a supply chain, providing insights into resource allocation and waste generation.
– **Data Science:** They are a great asset in data science, where Sankey diagrams can depict data transitions and feature interactions within machine learning algorithms.
– **Economic Analysis:** Tracking the distribution of money over various budgets or sectors within an economy is made simple through Sankey diagrams.
– **Transportation Studies:** Showcasing vehicle fuel consumption or comparing the transportation modes across different regions is a breeze with Sankey charts.
**Interpreting a Sankey Chart**
To interpret a Sankey diagram, follow this step-by-step approach:
1. **Understand the Inputs and Outputs:** Identify the nodes where the flow starts and ends.
2. **Locate Large Flows:** Look for the widest arrows, which provide insight into the largest quantities or rates of flow.
3. **Identify Efficiency:** Look at the flow distribution between sources and outputs to understand the efficiency of your process or system.
4. **Analyze Connections:** By examining the connections, you can identify where the flow is concentrated or where it could be streamlined.
Sankey charts are integral in understanding transitional data, serving as a visual tool to comprehend the hidden dynamics of complex systems. With their meticulous balance between simplicity and depth, they are an invaluable asset for anyone attempting to analyze the flow of transitions in the modern world. Whether you are an environmental scientist, data analyst, supply chain professional, or simply someone looking to better understand the world around you, the Sankey chart is a tool worth adding to your data visualization toolkit.
