A PSEUDO STEADY-STATE SOLUTION OF WATER MOVEMENT IN THE UNSATURATED ZONE OF THE SOIL

The vertical flow of moisture in the unsaturated zone of the soil is approached by a sequence of steady-state solutions of the flow equation. This technique allows an efficient simulation of the flow process over long periods, but restricts its application to permeable soils showing a relatively high groundwater table and to periods with either evaporation excess or rainfall excess. The pseudo steady-state solution of flow in the unsaturated zone has been incorporated a 3-dimensional mathematical model in order to solve field-size composite groundwater soil-moisture systems. Results have shown that the method is fast and sufficiently accurate, except for periods during which evaporation excess is followed by rainfall excess. A modification is suggested for bridging over periods during which evaporation excess changes into rainfall excess. The pseudo steady-state approach can also be used when the lower-boundary condition exists for a given depth of the groundwater table instead of the flux.

• Corporate Authors:

  Elsevier

  Radarweg 29
  Amsterdam,   Netherlands  1043 NX
• Authors:
  • De Laat, PJM
• Publication Date: 1976-5

Media Info

• Features: Figures; References;
• Pagination: p. 19-27
• Serial:
  • Journal of Hydrology
  • Volume: 30
  • Issue Number: 1/2

Subject/Index Terms

• TRT Terms: Evaporation; Flow; Flow equations; Groundwater; Mathematical models; Moisture content; Motion; Rainfall; Soil mechanics; Soil water; Steady state; Unsaturated soils; Water table
• Uncontrolled Terms: Moisture movement
• Old TRIS Terms: Groundwater level; Vertical flow
• Subject Areas: Geotechnology; Highways; Hydraulics and Hydrology;

Filing Info

• Accession Number: 00158177
• Record Type: Publication
• Files: TRIS
• Created Date: Sep 28 1977 12:00AM