Mathematical modelling of water and solute movement in ridge plant systems with dynamic ponding
Mathematical modelling of water and solute movement in ridge plant systems with dynamic ponding
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DOI：
10.1111/ejss.12503
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发表时间：
2018-03-01
影响因子：
4.2
通讯作者：
Roose, T.
中科院分区：
文献类型：
--
作者：
Duncan, S. J.;Daly, K. R.;Roose, T.
我们提出了一个数学模型，描述了水和溶质的运动在一个脊和沟的几何形状。我们专注于两个物理过程的影响：根吸水和池塘形成的犁沟。特别注意的是作为一个影响的瞬态降雨事件的积水的物理描述。我们关注的是发生在犁沟横截面上的现象，而不是沿着犁沟的排水。由此产生的模型包括一个耦合系统的偏微分方程和常微分方程描述的溶质运移，水运动和沟塘深度之间的数学相互作用。方程组的数值求解使用有限元技术。我们进行了数值模拟，以确定如何移动的溶质与低缓冲能力渗透到土壤中。我们考虑了两种情况：降雨量低，不会形成池塘，降雨量高，在犁沟中观察到明显的积水。我们发现，在根的存在下，移动的溶质收集到一个集中点附近的根系独立的降雨强度。在没有根的情况下，然而，我们观察到，积水渗透作为主要的运输机制移动的溶质。这导致了深溶质渗透到土壤中相比，非积水沟。
We present a mathematical model that describes the movement of water and solutes in a ridge and furrow geometry. We focus on the effects of two physical processes: root water uptake and pond formation in the furrows. Special attention is paid to the physical description of ponding as an effect of transient rain events. We focus on phenomena taking place in the furrow cross-section, not on the drainage along the furrow. The resulting model comprises a coupled system of partial and ordinary differential equations that describe the mathematical interplay between solute transport, water movement and furrow pond depth. The system of equations is solved numerically using finite element techniques. We conducted numerical simulations to determine how mobile solutes with low buffer powers penetrate into the soil. We considered two cases: low rainfall, in which pond formation does not occur, and high rainfall, in which significant ponding is observed in the furrows. We found, in the presence of roots, that mobile solutes collected into a concentrated spot adjacent to the root system independent of rainfall intensity. In the absence of roots, however, we observed that water infiltration from ponding acted as the dominant transport mechanism for mobile solutes. This resulted in deep solute penetration into the soil when compared with non-ponded furrows.