Transmissivity Feedback
One runoff process that contributes to interflow is transmissivity feedback. This occurs when a network of macropores is activated following rapid infiltration.
Macropores and natural pipes are void spaces in the soil that provide preferential pathways for water to move downslope. Decayed plant roots, burrowing insects and animals, and chemical reactions between water and soil minerals are a few ways that macropores form.
Macropore networks are more likely in deep-soiled areas with considerable organic materials. Thus, humid climates are more likely to have substantial interflow through macropore networks.