Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: 11/1/1998
Publication Date: N/A
Technical Abstract: The surface water balance of landfill covers is of critical concern in order to minimize percolation into contaminated areas. Depending on the time of the year and location of the site, near-surface processes of snowmelt, soil freezing, infiltration, and evapotranspiration become important in the water balance of a site and affect the behavior and reliability of a particular landfill cover design. Computer models can serve as useful tools to evaluate alternative landfill cover designs under a range of climate scenarios. The Simultaneous Heat and Water (SHAW) model is a detailed process model of heat, water and solute movement in a plant- snow-residue-soil system capable of simulating the effects of climate, slope, vegetation cover and management effects on near-surface conditions. Unique features of the SHAW model include detailed provisions for soil freezing and thawing and a detailed approach for simulating transpiration and heat transfer through a multi-species plant canopy. Although the SHAW model has had only limited application to landfill sites, its capability to simulate heat , water and solute transfer under a variety of environmental conditions has been tested. Previous applications of the model have demonstrated its capability to simulate near-surface processes impacting landfill cover effectiveness, including snowmelt, soil freezing infiltration, runoff, evapotranspiration and solute movement. The model's demonstrated ability for simulating the surface water and energy balance and water transfer within the soil profile make it a promising tool for evaluation of landfill covers and could be incorporated as part of a more comprehensive model for landfills.