 Hi everyone, I'm Aristeed from Metabolism of Cities and in this video I would like to talk to you about Sankey diagrams. Sankey diagrams is one of the essential visualizations that we have in material flow analysis and circular economy and we use this visualization to visualize material energy and waste flows that enter and exit in our economies. In a way, Sankey diagrams is kind of a synthetic illustration of a more data-intensive exercise. So perhaps you've never heard about them or perhaps you've seen them and you don't recognize them. So let me just show you very quickly what a Sankey diagram is and what it looks like. So this is an example of a Sankey diagram. Over here you see the material flows that enter and exit the European economy, so of the EU 27. What is this Sankey diagram? What does it show us and what can we learn from it? So let's go through this one and I'll explain it briefly. Basically, a Sankey diagram is also called a flow diagram and over here you see, as I said before, these are material flows that enter and exit your economy. You could think of that into, you know, it could be energy flows, it could be financial flows, it could be anything you want, but the idea is that you have two main components in a Sankey diagram. So you have flows, which are these elements over here that you can see. You can have them in different colors or you can have them in different sizes. We'll come back to that in a second and then you have nodes. So nodes is the places where your flow comes from and ends too. So you have a source node and a target node or an end node, let's say, and in between them you have a flow that connects them. So let's see what are these nodes and where are these flows. So for instance, let's see here up above we have imports. How many gigatons of material flows are imported into the European economy? So we have 1.7 billion tons that enter the European economy and we see that, well, here it's not really straightforward, but actually what this node represents is the rest of the world outside Europe and then it enters within Europe, let's say here. Down here below we have natural resources extracted. So where is this? This is within the European territory, EU 27. We extract from it 5.3 billion tons and over there you see that it starts from the natural environment within Europe and then it also goes to the direct material inputs. Now from this, the direct material inputs, then they go to process materials and you see that some more are added here. Recycling flows and backfilling flows are also entering the economy and are processed in order to be transformed into new products and materials. So you see here a couple of things, for instance the height or the how wide these flows are represents how big this flow is in terms of mass, in terms of, you know, euros if it's monetary terms. So in a quick glance you can see directly what are the most important flows in this diagram. So for instance, we see that we extract much more materials than we import in the European economy. Now of course, if you would like to dig further it's not exactly the same types of materials that you extract locally and that you import. So within the imports probably it's more fossil fuels and metals and in the natural extraction we have biomass and construction materials, in any case. What also is nice over here is that you see some circular flows going back to your city. So in that sense with one quick glance we know what are the flows, where they come from, where they end up, what are their proportions and what are some important flows and things to be careful for. So for instance, we see that when we talk about the circular economy in Europe we see that only a tiny fraction of our processed materials, so we have 8 billion tons of processed materials in 2019, only 1 billion ton is recircularized within the economy. So we can see this example in another place. So this is for the word, this time is more or less the same. The only difference is that we have differentiated some of the flows into colors. So this is something similar, it's the material flows that flow the global economy this time, not the European one. Over here you see in the down below what are the colors, so fossil fuels, biomass, metals, construction minerals and all of that. So you see that we can also have different colors and different numerous flows going from one node to another. So you can have from extraction, you have different types of materials that are extracted, you don't have let's say just materials, you can define them, you can say okay that much amount of biomass, that much amount of construction materials, etc etc. And then one important element over here that they have added is also stocks, so where flows stay for a while more than one year before they exit again. So this is another example of a Sankey diagram. If you are interested to learn more about Sankey diagrams, what other examples exist. We have within Metabolism of Cities, we have a multimedia library and if you click here on data visualization on the right you see that there are 178 data isolations that are found and if you click on that it brings you to the data visualization page and over here you will see other people that have done Sankey diagrams, so these can be inspirations for you if you would like to experiment in the future. There's also another website very interesting called Sankey diagrams, Sankey-diagrams.com where they just have Sankey diagrams, so you see numerous examples of Sankey diagrams but also what are the different tools that enable you to develop a Sankey diagram yourself and in the next video we will show you step by step how to create your own Sankey diagrams such as this one, we will show you where to get some data, how to process your data, what software to use, how to visualize it and then how to export it into a nice diagram. That's it for this video, if you like this video please don't hesitate to subscribe and also leave us a comment and say what you would like to see in the next videos, that way you're sure that you don't miss any new videos but also that help us to reach more people. Thanks again for watching and we'll see you in the next video. Cheers!