Introduction - Hydro-Environmental Analysis: Freshwater Environments - page 4

e water cycle

Water storage
in ice and snow

Water storage in the atmosphere

Condensation

Precipitation Transpiration

Evaporation

Surface runoff

Snowmelt runoff
to streams

Streamflow
Evaporation

Spring

Freshwater
storage

Water storage
in oceans

FIGURE 1.2 The hydrologic cycle. (From USGS, The hydrologic cycle (pamphlet), U.S. Government
Printing Ofice, Washington, DC, 1984a.)

Atmosphere
12.7

Ocean to land
Water vapor transport
40

Land
precipitation
113

Ocean
precipitation
373

Evaporation, transpiration 73

Ocean
evaporation 413

Ve getation

Land

Ice
26,350

Percolation

Rivers
Lakes
178

Ocean

Surface flow
40

Soil moisture
122

Ocean
1,335,040

Permafrost
22

Groundwater flow

Groundwater
15,300

FIGURE 1.3 Global water budget (units for reservoirs in 10 3 km 3 , and low in 10 3 km 3 yr -1 ). (From Trenberth,
K.E., Smith, L., Qian, T., Dai, A., and Fasullo, J., Journal of Hydrometeorology , 8, 758-769, 2007. With
permission.)