Abstract
The application of a model for the movement of water within waste dumps, described in a previous paper, requires the estimation of a range of physical characteristics. Parameters relating to the transfer of liquid water, water vapor, heat, and air within the waste dump must be estimated in addition to surface parameters which determine the interaction between subsurface processs and the atmospheric boundary layer. Three different methods are used to estimate the hydraulic conductivity and moisture retentivity: an inverse analysis based on field measurements of moisture movement; an application of the instantaneous profile method; and the Haverkamp‐Parlange method. The water vapor‐air diffusivity and intrinsic permeability of air are estimated, as well as the thermal properties of the various waste materials. The model presented previously is refined through a series of sensitivity analyses and applied to simulate the water movement observed within a lysimeter. Model predictions were particularly sensitive to the surface roughness. Evaporation from a bare surface was found to be related primarily to the surface moisture content, most evaporation occurring directly after rainfall. The contribution of vapor transport to cumulative evaporation was not significant in comparison to the contribution of liquid flow, even for long periods of dry surface conditions. Finally, the model is applied to predict the moisture movement within waste dumps that could be expected from an oil shale‐mining operation.
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