Infiltration and swelling under capillary flow

Authors: Wells, Robert - Rob

Submitted to: World Journal of Agriculture and Soil Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2019
Publication Date: 10/4/2019
Citation: Wells, R.R. 2019. Infiltration and swelling under capillary flow. World Journal of Agriculture and Soil Science. https://doi.org/10.33552/WJASS.2019.03.000562.
DOI: https://doi.org/10.33552/WJASS.2019.03.000562

Interpretive Summary: Upward/capillary water movement in a swelling soil is monitored and modeled in reference to the moving boundary of the soil surface and wetting front through an initially air-dry clay soil. The movement of the capillary water front, cumulative amount of infiltrating water, and resulting change in sample height are shown to be linear functions of the square root of time. A correction factor is applied to the capillary front arrival time (i.e. difference in distance between observed and measured moisture arrival at the probe) to match the increase in moisture with change in volume fraction of solid for a piecewise linear model.

Technical Abstract: The theory of water movement in swelling soils has experienced significant change since Haines, in 1923, first explored the relationships of expansion and subsidence. The present work deals with the swelling associated with the upward movement of water into an initially air-dry clay soil. The movement of the wetting front, cumulative imbibition, and change in sample height are shown to be linear functions of the square root of time. A linear piecewise model is used to estimate the change in the volume fraction of the solid resulting from an increase in the moisture content: relationships between ' and z, and ' and m result.