Sankey charts are a powerful and visually appealing way to represent flow data, allowing you to easily see the relationships between different data sets and the magnitude of the flows. These charts are named after the Scottish physicist Thomas Sankey, who first used them in the 19th century to represent the energy flows in steam engines.

In recent years, Sankey charts have become more popular as data visualization techniques have advanced, thanks in part to the availability of sophisticated charting tools and software. Today, you can easily create and integrate Sankey charts into a wide range of data-driven apps and websites, using tools like Tableau, Power BI, or even Python libraries like Plotly and Bokeh.

In this article, we’ll dive deep into the world of Sankey charts, exploring their creation and applications, and how they can help you unlock new insights into your data.

Creating Sankey Charts
Sankey charts consist of nodes and flows, where the width of the flow lines indicates the magnitude of the flow. To create a Sankey chart, you first need to define the nodes and their connections, which can involve several steps:

1. Identify your nodes: Nodes are typically the most significant categories or entities in your data. For instance, in a supply chain visualization, nodes might be suppliers, production facilities, distributors, and customers.
2. Map the flows: Flows represent the movement of information, materials, energy, or resources between the nodes. Each flow should have a source (the node it’s originating from), a target (the node it’s going to), and a value (the quantity, volume, amount, or intensity of the flow).
3. Organize your data: Input your nodes and flows into a structured data format, such as a CSV or Excel file, where each row represents a flow, and columns contain the node names and flow values.

Once you have your data organized, you can use various visualization libraries and tools to create your Sankey chart. For instance, using a library like Plotly in Python, your code might look something like this:

“`
import plotly.graph_objects as go

nodes = [‘Start’, ‘Processing’, ‘End’]
links = [
{‘source’: 0, ‘target’: 1, ‘value’: 30},
{‘source’: 1, ‘target’: 2, ‘value’: 20},
{‘source’: 1, ‘target’: 2, ‘value’: 10},
]
data = [
go.Sankey(
node = dict(
pad = 15,
thickness = 20,
line = dict(color = “black”, width = 0.5),
label = nodes,
color = [ “#99CCFF”, “#330066”, “#99CCFF” ]
),
link = dict(
source = list(map(lambda x: x[‘source’], links)),
target = list(map(lambda x: x[‘target’], links)),
value = list(map(lambda x: x[‘value’], links))
))
]
layout = go.Layout(title = “Simple Sankey Diagram”)
fig = go.Figure(data=data, layout=layout)
fig.show()
“`

This code snippet creates a simple Sankey diagram, but you can customize it according to your requirements, such as adding colors, labels, or more intricate visual elements.

Applications of Sankey Charts

Sankey charts have a wide range of applications across various domains, including business, engineering, environmental studies, and social sciences. Here are some popular use cases:

1. Energy flow analysis: Analyze the flow of energy in power grids, industrial processes, or energy consumption in different sectors (like transportation, residential, and commercial).
2. Supply chain management: Visualize the flow of goods, materials, or information between suppliers and customers in a supply chain, helping identify inefficiencies or bottlenecks.
3. Internet traffic analysis: Track and visualize the flow of data through the internet, such as website traffic, email exchanges, or social media interactions.
4. Environmental sustainability: Study the carbon footprint of different processes or the flow of resources in ecosystems.
5. Economic networks: Analyze trade flows or financial transactions between countries, sectors, or industries, helping policymakers and businesses make informed decisions.

Conclusion
Sankey charts harness the power of visual storytelling to communicate complex data flows in an intuitive and engaging way. By using these charts effectively, you can unlock insights that might be hidden in raw data, making your findings more accessible and impactful. Whether you’re looking to optimize processes, enhance data-driven decision-making, or simply convey information in an aesthetically pleasing manner, Sankey charts are an excellent tool to add to your data visualization arsenal.

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.