Project ID: 2002ID4B

Title: Physically Based Models for Hydraulic Properties of Swelling Soils

Project Type: Research

Focus Categories: Hydrology, Solute Transport, Agriculture

Keywords: Water Retention, Hydraulic Conductivity, Swelling Soils

Start Date: 03/01/2002

End Date: 02/28/2003

Federal Funds: $14996.00

Matching Funds: $30411.00

Congressional District: 1

Principal Investigator: Tuller, Markus (University of Idaho)

Abstract: Some of the most productive agricultural soils contain appreciable amounts of active clay
minerals and exhibit shrink-swell behavior in response to changes in soil water content and
chemical composition of the soil solution. Swelling and dispersion of clay minerals modify
hydraulic soil properties and lead to increased surface runoff with negative impacts on water
quality of rivers and lakes.

Furthermore, cracks forming in dry clay soils provide fast preferential pathways for rapid
transport of chemicals leading to potential risks for ground water contamination. In addition
to myriad agricultural management and engineering problems associated with changes in
mechanical properties and trafficability of such land surfaces, hydrologic predictions of
flow and transport processes are seriously hampered. Changes in soil volume and pore
space induced by shrink-swell behavior present a challenge to the development of predictive
models for flow and transport, in particular to the development of constitutive hydraulic
functions. Despite well-developed theory for crystalline and osmotic swelling of clay
minerals, translation of lamellar-scale theory to formulation of constitutive hydraulic functions
is lacking.

Progress/Completion Report PDF