Numerical Modelling of Soil-Atmosphere Interaction for Unsaturated Surfaces

• Published in: Proceedings of the Fourth International Conference on Unsaturated Soils 2006; Carefree, AZ; USA; 2-6 Apr. 2006 pp. 658 - 669
• Main Authors: Fredlund, M. D, Fredlund, D. G, Gitirana, Jr, G
• Format: Book Chapter Conference Proceeding
• Language: English
• Published: American Society of Civil Engineers (ASCE) 2006
• Subjects: Civil Engineering & Construction Materials; Environment & Environmental Engineering; General References; Infiltration; Numerical models; Unsaturated soils; Computation; Runoff; Evapotranspiration
• DOI: 10.1061/40802(189)51
• ISBN: 9780784408025; 0784408025

The computation of soil-atmosphere water fluxes such as infiltration, evapotranspiration, and runoff is required for the analysis of numerous problems in geotechnical, geoenvironmental engineering and hydrogeology. The soil-atmosphere interaction processes can be represented by a series of partial differential equations. This paper presents a PDE formulation that was developed for soil-atmosphere analysis and presents three cases demonstrating the application of the formulation developed to laboratory and fields conditions. Comparisons against experimental data show that evaporative fluxes can be successfully reproduced by theoretical models. The PDE solutions were used for the simulation of the fluxes through two soil cover configurations to exemplify the application of theoretical models to design. The results indicate that the manner how runoff is computed strongly affects the results. The numerical solutions appear robust and can be applied to the design of soil structures such as soil-cover systems, geo-hazard hazard quantification, and other unsaturated soil problems.