A semianalytical approach to spatial averaging of hydraulic conductivity in heterogeneous aquifers

JOURNAL OF HYDROLOGY

卷:216

Article

Pozdniakov, SP ; Tsang, CF

关键词: hydraulic conductivity;    heterogeneous media;    random media;    spatial variability;    effective parameters;    upscaling;   

DOI  :  10.1016/S0022-1694(98)00290-X

来源: Elsevier

【 摘 要 】

Numerical models of groundwater flow require hydraulic conductivity values for the gridblocks covering the flow domain. However, field conductivity data are usually measured at a different scale (usually smaller) than that of the gridblocks. The present paper describes an approach for upscaling to block-scale, which combines the rigorous result of small-value perturbation analysis with a plausible generalization of the first-order results to large variance. Steady-state flow through a block of stochastically heterogeneous medium, with constant values of the hydraulic head at the two opposite sides, is analysed. An upscaling rule and relationship is obtained between the local-scale hydraulic conductivity and the expected mean and variance of blockscale conductivity, where the block size is comparable with the correlation scale of the local conductivity held. The rather simple expressions that are obtained are validated using data from numerical experiments. Further, a generalized spatial power-averaging method to calculate the block-scale conductivity from values of local-scale conductivity is developed, in which the exponent value is given as a function of the ratios of how domain dimensions to the respective correlation length. Published by Elsevier Science B.V.

【 授权许可】

Free