Vertical flow of soil moisture, in situations with water application, drainage and evapo-transpiration, is investigated through theory in which the dynamic effects of both water and air are taken into account. The hydro-pneumatic properties of two model soils - a fine-grained loam and a medium-grained sand - are derived from publications by investigators worldwide. A system of equations for defining soil characteristics is described, which can be applied to any soil tested in a specified manner. Lacking sophisticated laboratory service, complete data for a project soil, for which two specific readily determined properties are known, can be estimated from those of the model soils by interpolation. A method of analysis utilizing finite differencing is developed and its application demonstrated by numerical examples in aquifer recharge and irrigation. The complex analytical problems arising from the hysteresis phenomenon in matrix potential, in situations where there is cyclic change in soil moisture content, are solved. (A)

  • Availability:
  • Corporate Authors:

    South African Institution of Civil Engineers

    P.O. Box 62129
    Marshalltown 2107,   South Africa 
  • Authors:
    • Wipplinger, O
  • Publication Date: 1990-3


  • Afrikaans

Media Info

  • Pagination: p. 91-
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00606337
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS, ATRI
  • Created Date: Mar 31 1991 12:00AM