|Sisson, J - IDAHO NATIONAL ENG. LAB|
|Tseng, P - U.C. RIVERSIDE|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: September 19, 1995
Publication Date: N/A
Technical Abstract: Data required to describe the K-h-theta functions throughout hysteresis loops are difficult to obtain. A laboratory column was instrumented with porous plates and a precision water pump. The pump incremented steady flow rates. Soil-water tensions and water contents were measured in an initially dry dune sand. These data were used to estimate the main wetting curve for the K-h-theta hysteresis function. Once saturation was achieved, the pump decremented steady flow rates and the main-drying curve for the K-h-theta hysteresis function was obtained. The pump control and data acquisition were fully automated and, therefore, obtaining scanning loops is possible. Obtaining data for measuring the hysteretic behavior of the K-h-theta function normally takes months of tedious work, but we obtained the data needed in less than one month.