Water cycle processes Flashcards
Evaporation
When solar radiation causes liquid water to change state into a gas (ocean- 413 thousand km3/yr)
Condensation
When air cools to the dew point and causes excess water vapour to convert into liquid water using condensation nuclei (73 thousand km3/yr)
Cryospheric processes
The processes that effect the total mass of ice at any scale (via accumulation and ablation)
Accumulation
The acquisition or build up of ice
Ablation
The loss of ice
Precipitation
The product of the condensation of atmospheric water vapour which falls from the clouds due to gravitational pull (land- 113 thousand km3/yr , ocean- 373 thousand km3/yr)
Throughfall
The portion of the precipitation that reaches the ground directly through gaps in the vegetation canopy and drips when canopy-surface rainwater exceeds its storage capacity
Stemflow
The portion of precipitation intercepted by the canopy that reaches the ground by flowing down stems, stalks, or tree boles
Infiltration
The downward movement of water from the surface into the soil
Throughflow
The movement of water downslope through the subsoil under the influence of gravity
Percolation
The downward movement of water within the rock under the soil surface
Groundwater flow
The slow movement of water through underlying rocks
Overland flow
The tendency of water to flow horizontally across land surfaces when rainfall has exceeded the infiltration capacity of the soil and all surface stores are full/overflowing (40 thousand km3/yr)
Transpiration
The loss of water from vegetation through pores on their surface
Evapotranspiration
The total output of water from the drainage basin directly back to the atmosphere (73 thousand km3/yr)
