摘要
多孔介质中水流和溶质运移特性问题是地下水污染的研究基础,但其变流速与弥散度的尺度效应耦合作用对溶质运移的影响尚未完全清楚。基于对流弥散方程,构建了考虑随时间和空间指数变化的地下水流速及弥散度的一维溶质运移模型,利用积分变换及Laplace变换获得了半解析解。研究表明,指数变化的流速与尺度效应耦合作用导致穿透曲线(Breakthrough curves,BTCs)发生了明显变化,地下水流速的衰减及弥散度的尺度效应均能导致穿透曲线的拖尾,稳定速度的增加会增大对流作用,导致穿透曲线峰值增大,拖尾现象减弱。总之,在描述地下水溶质运移过程时,随时间和空间变化的流速及弥散度的影响不可忽视。
The properties of flow and solute transport in porous media is fundamental to study groundwater pollution,and the effect of the coupling of the scaling effect of dispersion and variable velocity on solute transport is not yet fully understood.In this study,a one-dimensional solute transport model is constructed based on the advection-dispersion equation,which considers the temporally exponential groundwater flow velocity and exponentially distance-dependent dispersion,and a semi-analytical solution is obtained using the integral and Laplace transforms.The study shows that the coupling of exponentially varying flow velocities and scale effects leads to significant changes in properties of breakthrough curves(BTCs).The decay of groundwater flow velocity and scale effect of dispersion can lead to trailing of the breakthrough curves.The increase of steady velocity heightens convection,which leads to an increase in the peak of the breakthrough curves and a weakening of the trailing phenomenon.In conclusion,the effects of time-dependent flow velocity and distance-dependent dispersion cannot be ignored when describing groundwater solute transport processes.
作者
李艳芳
Li Yanfang(Erdos City Guoneng Shendong Supervision Co.LTD,Eerduosi 719315,China)
出处
《黑龙江科学》
2023年第8期7-12,共6页
Heilongjiang Science
关键词
溶质运移
变流速
尺度效应
对流-弥散方程
Solute transport
Variable flow velocity
Scale effects
Advection-Dispersion Equation
