Glossary of hydrological processes

advection

horizontal movement of air

baseflow

transmission of groundwater and streamflow discharged from the groundwater zone

condensation

change in state of water from vapour to liquid

convection

vertical movement of air

deep outflow

flow of groundwater at depth, in some cases between drainage basins

diffusion

movement of capillary water according to moisture gradients

drippage

fall of water droplets from vegetation to the ground

evapouration

change in state of water from a liquid to a vapour

infiltration

transfer of water from the ground surface into the soil zone

interception

storage of precipitation by vegetation canopy

interflow (throughflow)

the transmission of soil water parallel to the ground surface

laminar flow

flow of water in thin layers

precipitation

transfer of solid and liquid water from the atmosphere to the earth

runoff

flow of water over the earth's surface, including overland flow (unconfined) and streamflow (confined)

seepage (percolation)

movement of gravity water through the soil and groundwater zones

stem flow

movement of intercepted water down the trunks of trees or stems of vascular plants

stormflow (quickflow)

streamflow derived from channel precipitation, runoff and rapid interflow

sublimation

change of state of water between a solid and a vapour

throughfall

precipitation that reaches the ground directly, (i.e.) without being intercepted

translatory flow

displacement of antecendent soil water by the infiltration of new rainwater or snow meltwater

transmission

flow of soil water and groundwater in response to gravity

transpiration

diffusion of water vapour through stomata on the underside of leaves

turbulent flow

flow that involves the exchange of mass and energy (eddies) between different parts of the flow