SOIL MOISTURE MOVEMENT BY TEMPERATURE GRADIENT

Results from a one-dimensional analytical model and experiments showed that redistribtuion of moistrue due to temperature gradients was maximum when initial saturation was about 20%. Increase in moisture at the cold end was then on the order of 0.03 g/cu cm or 1.2% by weight, after 3 days at a temperature gradient of 0.9 degrees C/cm and about 80% of this in the first day. At low moisture content the absorbed water is held firmly relative to diffusion due to vapor concentration gradient and only insignificant redistribution takes place. A layer of fine initially dry material would absorb water until all the absorbed water requirements are satisfied. Since the vertical movement of moisture due to temperature gradients was found to be insignificant, any buildup of moisutre in the base course must result from other causes, either seepage through the top seal or lateral movement. For lateral movement, temperature gradients could be important because movement from berms under the cooler seal at nighttime is followed by movement vertically down during the day, possibly leading to eventual moisture accumulation. /ASCE/

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Filing Info

  • Accession Number: 00149205
  • Record Type: Publication
  • Report/Paper Numbers: ASCE #12645
  • Files: TRIS
  • Created Date: Mar 30 1977 12:00AM