Seasonal water uptake near trees: a numerical and experimental study
Seasonal water uptake near trees: a numerical and experimental study
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树木附近的季节性吸水量：数值和实验研究
DOI：
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发表时间：
2006
期刊：
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通讯作者：
N. Ali
中科院分区：
文献类型：
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作者：
S. Rees;N. Ali
本文探讨了与非饱和区和成熟树木附近水分迁移模式数值模拟相关的问题。该研究基于使用包含汇项的不饱和湿气流动理查德方程。通过空间离散化的有限元方法和有限差分时间推进方案获得了数值解。开发了轴对称解决方案来表示已建立的树木附近的吸水量。所采用的方法利用径向对称性并假设水提取率随深度和半径呈线性分布。该模型已通过直接与（其他人）记录的位于巨石粘土底土上的成熟椴树的现场测量结果进行比较而得到验证。非线性水力特性是从独立发表的数据中获得的。现场数据与模拟结果之间取得了良好的相关性。该模拟涵盖了从冬季田间容量开始的完整年度周期，一直延伸到整个春夏干燥期以及随后的秋季补给。据信，这是第一次尝试在这样的时间尺度上模拟已建立的树的行为。这种相对简单的方法被认为适合开发和应用于一系列地球工程问题（例如边坡稳定性、收缩/隆起预测等）。
Issues related to the numerical simulation of moisture migration patterns in the unsaturated zone and in the vicinity of mature trees are explored in this paper. The research is based on the use of Richard's equation for unsaturated moisture flow incorporating a sink term. A numerical solution has been achieved via the finite-element method for spatial discretization along with a finite-difference time-marching scheme. An axisymmetric solution is developed to represent water uptake near an established tree. The approach adopted utilizes radial symmetry and assumes a linear distribution of water extraction rates with both depth and radius. The model has been validated by direct comparison with field measurements recorded (by others) for a mature lime tree located on a boulder clay subsoil. Non-linear hydraulic properties have been obtained from independent published data. A good correlation between field data and simulated results has been achieved. The simulation covers a full annual cycle starting from field capacity in winter, extending through a full spring–summer drying period and subsequent autumn recharge. It is believed that this is the first attempt to simulate the behaviour of an established tree over such a time-scale. This relatively straightforward approach is thought to be suitable for development and application to a range of geo-engineering problems (e.g. slope stability, shrinkage/heave prediction, etc).