The global water cycle

Question 1

What is the global water cycle

Answer 1

A closed system between the atmosphere, the oceans, land and the biosphere, timescales of transfer rates vary from days to millions of years

Question 2

What is residency time

Answer 2

Describes the average length of time water stays in each reservoir

Question 3

What are the major stores

Answer 3

Atmosphere - smallest store
Land
Ocean - largest store

Question 4

What are the major processes of the water cycle

Answer 4

Precipitation
Evapotranspiration
run-off
Groundwater flow

Question 5

Inputs of water to the atmosphere

Answer 5

Water vapour evaporated from the oceans, soils, lakes and rivers
Vapour transpired through the leaves of plants

Question 6

Water leaving the atmoshpere

Answer 6

Precipitation - rain, snow, hail
Condensation - fog
Ice sheets, glaciers and snowfields release water by ablation

Question 7

Water on the land

Answer 7

Precipitation and melt-water drain from the land surfaces as run-off into rivers
Most rivers flow into oceans
Precipitation reaches rivers after infiltrating the soil
Water in the soil may percolate into permeable rocks