Geography- Water Security Definitions (Hydrological Cycle)

Precipitation

Any form of moisture that falls from clouds and reaches Earth's surface.

Infiltration

When water travels from the surface of the earth into the ground beneath

Surface Run- off

When water travels across the surface of the earth

Channel flow

Water that is travelling in rivers or streams

Through fall

Water that passes directly through a canopy or is initially intercepted by above ground vegetative surfaces and subsequently drips from the canopy

Leaf drip

Intercepted precipitation that gradually drips off leaves onto the ground

Stem flow

When intercepted water drains from outlying leaves and branches and is channeled to the stems and trunks of vegetation

Percolation

When water travels deeper into the ground, form unsaturated ground into saturated ground

Groundwater flow

The movement of water through saturated ground, known as aquifer

Aquifer

A body of rock or sediment that stores groundwater and allows the flow of groundwater

Through- flow

The lateral movement of water through unsaturated ground, close to the land surface

Interception

When an object stops precipitation from reaching the ground beneath

Vegetation storage

All moisture stored in vegetation

Surface storage

Any water that is held on the surface of the earth. Some surface stores like puddles may only be temporary.

Soil moisture storage

Water that is stored below the surface in unsaturated ground

Groundwater storage

Water that is stored in saturated ground.

Channel storage

The volume of water contained within the banks of a river will operate as a water store between its initial input and ultimate output

Evaporation

Liquid water from surface stores and rivers turning into water vapour (gas)

Transpiration

Liquid water evaporating from vegetation

River runoff/discharge

Eventually most rivers enter the sea and discharge the river's flow into the sea.