Non-steady-state modelling of water transfer in a Mediterranean evergreen canopy
Non-steady-state modelling of water transfer in a Mediterranean evergreen canopy
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DOI：
10.1016/s0168-1923(01)00218-0
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发表时间：
2001-05-02
影响因子：
6.2
通讯作者：
Rambal, S
中科院分区：
文献类型：
--
作者：
Lhomme, JP;Rocheteau, A;Rambal, S
设计了一个模拟地中海气候条件下欧洲栎（Quercus ilex）冠层水分转移日变化的模型。它结合了非稳态水力模型和蒸腾模型。水力模型包括由电容表示的水库、土壤-植物水力阻力和连接到电容的存储水力阻力。它模拟了水分吸收和储存流的日变化，从日蒸腾过程作为输入。蒸腾模型基于Penman-Monteith方程和气孔阻力的Jarvis-type表示（即，最小气孔阻力乘以独立应力函数的乘积）。同时测量冠层蒸发的涡度相关系统和从土壤中吸收的液流测量水分允许一个校准和验证模型。已发现电容等于0.17 mm MPa-1（具有约2 MPa h mm（-1）的储存水力阻力），在蒸腾速率和从土壤中吸水之间产生约1 h的时间滞后。水力模型正确地代表了实验数据。蒸腾模型提供了合理的估计，但有显着的分散。该组合模型直接从环境变量模拟了水分吸收、储存流和蒸腾速率的日变化，但在后一种情况下，储存流的估计精度相当差。(C)2001 Elsevier Science B. V.保留所有权利。
A model simulating the diurnal pattern of water transfer within a Helm oak (Quercus ilex) canopy in Mediterranean conditions has been designed. It combines a non-steady-state hydraulic model with a transpiration model. The hydraulic model includes a reservoir represented by a capacitance, a soil-plant hydraulic resistance and a storage hydraulic resistance connected to the capacitance. It simulates the diurnal variation of water uptake and storage flow from the diurnal course of transpiration used as input. The transpiration model is based upon the Penman-Monteith equation and a Jarvis-type representation of the stomatal resistance (i.e., a minimum stomatal resistance multiplied by the product of independent stress functions). Simultaneous measurements of canopy evaporation by an eddy covariance system and water uptake from the soil by sap flow measurements have allowed one to calibrate and validate the model. The capacitance has been found to be equal to 0.17 mm MPa-1 (with a storage hydraulic resistance of about 2 MPa h mm(-1)), generating a time lag of about 1 h between the transpiration rate and the water uptake from the soil. The hydraulic model correctly represents the experimental data. The transpiration model provides reasonable estimates, but with a significant scatter. The combined model simulates the diurnal variation of water uptake, storage flow and transpiration rate directly from environmental variables, but in this latter case, the storage flow is estimated with a rather poor accuracy. (C) 2001 Elsevier Science B.V. All rights reserved.