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Modeling soil seal as a nonuniform layer
Author(s) -
Mualem Y.,
Assouline S.
Publication year - 1989
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/wr025i010p02101
Subject(s) - loam , hydraulic conductivity , compaction , geotechnical engineering , soil science , geology , loess , bulk density , porosity , soil water , seal (emblem) , flow (mathematics) , soil compaction , mechanics , geomorphology , art , physics , visual arts
A quantitative conceptual model of soil sealing is proposed, based on the assumption that the compaction of the upper soil layer by raindrops and the “washed in” material result in a nonuniform change in bulk density, which can be approximated by an exponential function. The change in density causes in turn variations in soil properties, such as porosity, water retention, and hydraulic conductivity. Empirical functions are suggested to simulate the pattern by which these properties vary as dependent upon the density change. The model was calibrated using data of two experimental studies related to crust properties of three different soils: sandy loam, loam (loess), and clay loam. The model reproduced quite well the observed features of the experimental sealing characteristics. Seals developed in two different flow systems subjected to simulated rain were analyzed: (1) seal developed under saturated conditions over a shallow soil bed and (2) seal developed under unsaturated flow conditions. The proposed model highlights some soil parameters that are quite important and should be observed in soil sealing investigations. It also presents a basis for quantitative analysis of the soil sealing phenomenon in terms of measurable physical parameters.