Interflow
In hydrology, interflow is the lateral movement of water in the unsaturated zone, or vadose zone, that returns to the surface or enters a stream.[1] Interflow is sometimes used interchangeably with throughflow;[1] however, throughflow is specifically the subcomponent of interflow that returns to the surface, as overland flow, prior to entering a stream or becoming groundwater.[2] Interflow occurs when water infiltrates (see infiltration (hydrology)) into the subsurface, hydraulic conductivity decreases with depth, and lateral flow proceeds downslope.[1] As water accumulates in the subsurface, saturation may occur, and interflow may exfiltrate as return flows, becoming overland flow.[1]