• Brutsaert, W. 1982. Evaporation into the Atmosphere. Kluwer Academic, 309 pp.

  • Komatsu, T. S. 2001. Evaporation speed of water from various soil surfaces under calm state. J. Phys. Soc. Japan 70:37553756.

  • Kondo, J., , N. Saigusa, , and T. Sato. 1990. A parameterization of evaporation from bare soil surfaces. J. Appl. Meteor. 29:385389.

  • Mahfouf, J. F., and J. Noilhan. 1991. Comparative study of various formulations of evaporation from bare soil using in situ data. J. Appl. Meteor. 30:13541365.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 76 76 5
PDF Downloads 28 28 3

Toward a Robust Phenomenological Expression of Evaporation Efficiency for Unsaturated Soil Surfaces

View More View Less
  • 1 Department of Environmental Sciences, Japan Atomic Energy Research Institute, Tokai, Naka, Ibaraki, Japan
© Get Permissions
Restricted access

Abstract

The evaporation rates of water from several soil types were measured under controlled conditions. When the layer of soil is sufficiently thin, the evaporation efficiency β, the ratio of the evaporation rate from the soil surface relative to that from the watered surface, is described well by a function of the mean volume fraction θ of water. The function has a common form for several types of soil and can be parameterized by a single parameter, the characteristic volume fraction θc of water, as β = 1 − exp(−θ/θc). The value of θc depends on the soil type and also on the wind speed. The latter dependence can be robustly described in terms of the evaporation resistance for the watered surface. These findings are expected to become a basis for calculating the evaporation efficiency for the soil with an arbitrary depth in a systematic way.

Corresponding author address: Teruhisa S. Komatsu, Department of Physics, Gakushuin University, Mejiro 1-5-1, Tokyo 171-8588, Japan. teruhisa.komatsu@gakushuin.ac.jp

Abstract

The evaporation rates of water from several soil types were measured under controlled conditions. When the layer of soil is sufficiently thin, the evaporation efficiency β, the ratio of the evaporation rate from the soil surface relative to that from the watered surface, is described well by a function of the mean volume fraction θ of water. The function has a common form for several types of soil and can be parameterized by a single parameter, the characteristic volume fraction θc of water, as β = 1 − exp(−θ/θc). The value of θc depends on the soil type and also on the wind speed. The latter dependence can be robustly described in terms of the evaporation resistance for the watered surface. These findings are expected to become a basis for calculating the evaporation efficiency for the soil with an arbitrary depth in a systematic way.

Corresponding author address: Teruhisa S. Komatsu, Department of Physics, Gakushuin University, Mejiro 1-5-1, Tokyo 171-8588, Japan. teruhisa.komatsu@gakushuin.ac.jp

Save