Daily evaporation from drying soil: Universal parameterization with similarity

作者：Brutsaert Wilfried^*

来源：Water Resources Research, 2014, 50(4): 3206-3215.

DOI：10.1002/2013WR014872

• evaporation
• drying soil
• soil-controlled evaporation
• falling rate evaporation
• second stage evaporation
• weighted mean diffusivity

With supporting experimental evidence from three separate field studies of daily mean evaporation from bare soil with vastly different physical characteristics, it is shown that the process can be described as isothermal linear diffusion in a finite depth domain. The resulting solution leads directly to similarity variables and thus a universal parameterization, which should in principle be applicable to most field soils. In addition, a closed form expression is presented to estimate the weighted mean diffusivity for exponential type soil water diffusivities. In this solution, the widely used square root of inverse time proportionality of this phenomenon is its short time version, whereas the exponential decay proportionality, proposed however by several authors for vegetated surfaces, is its long time version. It appears that in many situations the soil layer contributing to evaporation is fairly shallow and only a few tens of centimeters thick.

• 出版日期2014-4