Sunkey Diagram (桑基图)
Sankey diagrams are a type of flow diagram in which the width of the arrows is proportional to the flow rate.
Sankey diagrams can visualize the energy accounts, material flow accounts on a regional or national level, and cost breakdowns.
Sankey diagrams emphasize the major transfers or flows within a system. They help locate the most important contributions to a flow. They often show conserved quantities within defined system boundaries.