4.1.4—Hydrological cycle flows

Syllabus
First assessment 2026
Objective
4.1.4
Level
HL

Sort and Sequence Water Flows

Transformations change water state; transfers move water, and infiltration is entry into soil while percolation is movement through it.

Evaporation, transpiration, condensation, freezing, melting and sublimation involve a change of state or release of water vapour. Advection moves vapour, liquid droplets or ice crystals horizontally; precipitation, surface run-off, streamflow and groundwater flow transfer water between locations.

Rain infiltrates the surface, then percolates through porous soil toward groundwater.

Advection is wind-driven horizontal transfer of water in the atmosphere; condensation changes vapour into liquid and precipitation transfers water from atmosphere to surface.

Infiltration and percolation are sequential but not synonyms.