as pdf

Soil Water Evaporation
• Stage 1. For soils saturated to the surface, the evaporation
rate is similar to surface water evaporation.
• Stage 2. As the surface dries out, evaporation slows to a rate
dependent on the capillary conductivity of the soil.
• Stage 3. Once pore spaces dry, water loss occurs in the form
of vapor diffusion. Vapor diffusion requires more energy input
than capillary conduction and is much, much, slower.
Note that for soils under a forest canopy, R net , vapor pressure
deficit, and turbulent transport (wind) are lower than for
exposed soils.