Quantitative relationship between soil structure and preferential flow and transport in contrasting soils and land uses

HR: 1340h
AN: H23G-1717 [Abstracts]
TI: Quantitative relationship between soil structure and preferential flow and transport in contrasting soils and land uses
AU: * Luo, L
EM: lxl230@psu.edu
AF: Penn State Univ., 116 ASI Blg, University Park, PA 16802, United States
AU: Lin, H
EM: henrylin@psu.edu
AF: Penn State Univ., 116 ASI Blg, University Park, PA 16802, United States
AU: Walker, C
EM: cww118@psu.edu
AF: Penn State Univ., 116 ASI Blg, University Park, PA 16802, United States
AB: The elusive relationship between preferential flow dynamics and soil structure is a main factor prohibiting accurate estimation of flow and transport in structured soils. It is essential to develop quantitative relationships between soil structure (especially pore network) and soil hydraulic properties. Recent advance in computed tomography (CT) provides a promising tool to non-invasively observe soil structure. Two soils with contrasting textures and structures (Hagestown and Morrison) and land use (crop and pasture) were investigated in this study. Five soil cores (10 cm in diameter and 30 cm in length) were taken for each land use-soil type combination. The soil columns were scanned using X-ray CT to obtain soil structural parameters (pore size distribution, pore length density, pore hydraulic radius, pore continuity, pore connectivity fractal dimension, and lacunarity). The chemical breakthrough experiments were then conducted on each soil column and the parameters related to preferential flow and transport were reversely estimated (including dispersion coefficient, mass transfer coefficient, and the fraction of macropores). The resultant two sets of the parameters are being analyzed to quantitatively relate soil structure to preferential flow and transport. This study is expected to enhance our understanding of fundamental processes and quantitative relationships for predicting preferential flow and transport at the soil pore to column scales.
DE: 0486 Soils/pedology (1865)
DE: 1847 Modeling
DE: 1865 Soils (0486)
SC: Hydrology [H]
MN: 2007 Fall Meeting