Publications Details
The distribution of moisture beneath a two-dimensional surface source; Yucca Mountain Site Characterization Project
The distribution of moisture beneath a two-dimensional strip source is analyzed by applying the quasi-linear approximation. The source is described by specifying either the moisture content or the infiltration rate. A water table is specified at some depth, D, below the surface, the depth varying from shallow to semi-infinite. Numerical solutions are determined, via the boundary integral equation method, as a function of material sorptivity, {alpha}, the width of the strip source, 2L, and the depth to the water table. The moisture introduced at the source is broadly spread below the surface when {alpha}L {much_lt} 1, for which absorption by capillary forces is dominant over gravity-induced flow. Conversely, the distribution becomes finger-like along the vertical when {alpha}L {much_gt} 1, where gravity is dominant over absorption. For a source described by specifying the moisture content, the presence of a water table at finite depth influences the infiltration through the source when {alpha}D is less than about 4; infiltration rates obtained when the water table depth is semi-infinite are of sufficient accuracy for greater values of {alpha}D. When the source is described by a specified infiltration flux, the maximum allowable value of this flux for which the material beneath the source remains unsaturated is determined as a function of nondimensional sorptivity and depth to the water table. 30 refs., 16 figs., 2 tabs.