Temperature and Soil-Water Diffusivity Relations
1963
Jackson, Ray D.
AsbstractWater at -2mb pressure was absorbed by horizontal columns of three soil materials of differing texture at temperatures of 5.0°, 13.5°, 24.0°, 33.0°, and 42.5°C. From the water content distributions, soil-water diffusivities were calcualted, assuming applicability of diffusion theory. Twofold to threefold differences were observed between diffusivities at 5.0° and 42.5°C. The water content distribution curves were not measurably influenced by temperature, thus, in the equation used to calculate diffusivity, the time required for water to penetrate the given distance was the only term differing with temperature. The temperature dependence of the ratio of surface tension to viscosity appears to be the dominant factor in describing the temperature dependence of soil-water diffusivity. The square root of the surface tension viscosity ratio adequately acounts for the temperature dependence of penetrability and sorptivity.
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