Figure 2.

Diagram illustrating the four elements of propagation events (modified from Reiners and Driese, 2003). Different conveyed entities (materials or energy) are portrayed by different colors and shapes. These entities are propagated (dashed lines) along the conveyance vector and describe different functional connections. Entity changes in magnitude (portrayed by size) and form (portrayed by shape) are illustrated as examples of source (white squares), transformation (black symbols), lag and sink (white circles) functions that can occur en route to the locus of consequence (i.e., downstream water).