Insights from Sankey diagram

Goal: Generate insights from the Sankey diagram


  1. After generating the Sankey diagram, drag your flows around until they are in a good legible order.
  2. Ask yourself the exemplary questions below, reading the Sankey diagram from left to right.
  3. Note down the various insights that can be gained from the Sankey, as explained in the video. (4. If you are using the SCA online report, you can fill in the following fields 14, 18, 19 and 20 of the report form: 14 Describe the Sankey diagram, 18 Insights on status quo, 19 Upscaling (or reflect on) DAs, 20 Recommendation for making the sector more circular.)

Exemplary questions for analysis

  • What stands out to you at first sight?
  • What is the most prominent material in terms of extraction/import/export/waste?
  • Is your city consuming materials that are directly extracted from your territory or do you import (most of) them?
  • Is your city treating its waste locally or exporting it?
  • What is the quantity of materials that is staying within the material loop?

Outline of the video

  • In Sankey diagrams the flows are as thick as the mass is. See here for the material flow diagram from Eurostat. It helps to understand where flows come from and where they go. This can be done for several materials.
  • Interpretation of the Sankey
    • It can tell you how dependent you are on imports.
    • Material use: how much stays in your city, how much you use, how much you waste.
    • It helps to check orders of magnitude
    • Looking at circular flows. You can see how much circles back and also how big those values are compared to the processed or used materials.
  • You can translate those insights into recommendations in the Data analysis part of a report.
  • As for the demonstration actions (DAs) and their upscaling, you need to consider where in the Sankey they are located and if there are gaps. If there are no DAs in some “problem areas”, those where changes would need to be made, it might give you ideas that there DAs could be useful to implement.
  • State demonstration actions of your city and their “size”, meaning how much material they can handle per year (put things in perspective, what is their impact and how much more effort is needed to “become circular”).
  • Determine potential by analysing how much material there is per year.
  • Recommendation for making the sector more circular (field 20 in the report form): You can state here which of the DAs should be upscaled. Moreover, you can also add here that you need to develop a circularity process for the sector, define some main objectives and develop an action plan. You can also state that more information on a certain material is needed or that other materials should be included in the analysis.