摘要
采用粒子平均移动的概念和理论,推导出土壤水动力弥散系数分形模型。模型参数包括粒子实际的无规则运动所产生的的弥散系数α0,描述土壤结构和非均匀性对于水动力弥散系数影响的系数β和分形维数D。实测资料验证表明,所提出的模型能够较好的反映土壤水动力弥散系数与尺度的关系。参数分析表明,分形维数D和参数β分别描述土壤非均质性和土壤结构对水动力弥散系数的影响,移动距离方差有随α0的增大而增加的趋势。
In this study, a fractal approach was used to describe the relationship between horizontal travel distance and actual travel distance of chemical particles. Based on the theory of mean travel distance of particles, we derived a scale dependent model of soil dispersivity, including three parameters： the fractal dimension D, a parameter （α0） to characterize the dipersivity along the actual travel routines, and a parameter （β） related to soil properties. Experimental data were used to evaluate the proposed model and a good agreement was achieved. The fractal dimension D was related to soil heterogeneity. The parameter β was used to describe the effect of soil structure on soil dispersivity. Variance of particle travel distances increased with αo.
出处
《灌溉排水学报》
CSCD
北大核心
2006年第1期1-5,共5页
Journal of Irrigation and Drainage
基金
国家自然科学基金项目资助(50279038
50239090)
