CAJ | 학술논문

利用Voronoi图逐级碎裂方法,在二维正方网格上构造出不同等级的虚拟土壤来仿真具有丰富孔隙结构的真实土壤,并借助于随机行走模型,数值模拟了溶质粒子在该虚拟土壤中的迁移行为.结果表明,溶质粒子表现出反常扩散行为.对有偏倚的随机行走模型,其均方位移与时间呈正比关系＜r~2(t)＞∝t~K,即扩散系数D=K-1,长时间的K值更大,溶质粒子扩散更快;首次穿越时间满足正态对数分布,说明溶质粒子迁移是一阶随机过程;由连续时间随机行走理论,发现溶质粒子扩散非费克现象明显.同时发现不同的土壤孔隙结构及随机行走类型所对应的拟合参数不同,即它们也影响溶质粒子的迁移行为.该研究有利于人们从理论上定性理解和预测水及溶质在有大孔隙土壤中的迁移,保护地下水环境.
이용Voronoi도축급쇄렬방법,재이유정방망격상구조출불동등급적허의토양래방진구유봉부공극결구적진실토양,병차조우수궤행주모형,수치모의료용질입자재해허의토양중적천이행위.결과표명,용질입자표현출반상확산행위.대유편의적수궤행주모형,기균방위이여시간정정비관계＜r~2(t)＞∝t~K,즉확산계수D=K-1,장시간적K치경대,용질입자확산경쾌;수차천월시간만족정태대수분포,설명용질입자천이시일계수궤과정;유련속시간수궤행주이론,발현용질입자확산비비극현상명현.동시발현불동적토양공극결구급수궤행주류형소대응적의합삼수불동,즉타문야영향용질입자적천이행위.해연구유리우인문종이론상정성리해화예측수급용질재유대공극토양중적천이,보호지하수배경.
Virtual soils, rich in macropore, but different in level, were constructed with the aid of the Voronoi tesselation algorithm on two dimensional lattices and transport behaviors of solute particles therein numerically simulated using random walk models. It was found that the solute diffusion was anomalous and its mean square of displacement was positively correlated with time, being ＜(r→)~2(t)＞∝t~K. Values of K depended on the types of soils and the types of random walk models. With biased random walk models, the values increased with the time, which means the particles diffused faster with the time went on. The first passage time of solute transport satisfied the logarithmic normal distribution. Non-fick effect of the diffusion was obvious with the continuous time random walk theory. And it was found that soils different in por structure would have different corresponding fitting parameters with the random walk models, that is to say, they also affected the transport behaviors of solute particles. The findings of the study are found to be helpful to researchers in understanding and predicting behaviors of water and solutes in macroporous soil, and hence in helping protect the underground water environment.