地下水非平稳随机模型及空间变异性与非均匀性相互关系研究的展望

Advancement of stochastic modeling for non-stationary groundwater transport and interaction between small-scale heterogeneity and large-scale non-uniformity

本文在对地下水空间变异性现场的调查研究、大尺度示踪试验和数值模拟研究的结果进行比较分析的基础上,指出平稳随机的假定不能真实反映空间小尺度变异性与大尺度非平稳性间的相互作用,而现有的随机方法需要分辨小尺度的动力特性,因此在实际应用中受到极大限制。本文还从CPU、内存需求和方程求解难易程度等角度出发,在客观评述现有地下水随机模型基础上,对非平稳谱方法在研究变异性与非平稳性相互作用方面的应用前景作了初步展望,认为该方法将使得对实际现场尺度下的流动和输运过程的直接模拟成为可能。

A review of the field-scale site investigation on spatial small-scale heterogeneity and existing stochastic numerical techniques is presented. It is pointed out that the stationary-based stochastic theories are very difficult or impossible to be applied to predict and quantify the interaction between small-scale heterogeneity and large-scale non-uniform in practical situation. The current stochastic numerical techniques have been limited to small and mostly hypothetical problems because stochastic numerical techniques available required resolving uncertain small-scale dynamics before the techniques can be used to quantify the field-scale impact. In this paper, from the view point of the required CPU, memory and difficulty of the equation to be solved, the potential perspective of Non-stationary Spectral Method(NSM) to be applied to predict and quantify the interaction between small-scale heterogeneity and large-scale non-uniform is evaluated. By using this approach the direct simulation of stochastic groundwater flow and transport under realistic condition will become possible.