蒸发的阻抗模型讨论

蒸发的阻抗模型,从简单的单层模型到复杂的多层模型,应用日益广泛。目前文献中流行一种看法:单层阻抗模型没有牢固的物理基础,但简单易行;而多层模型才具备可靠的物理基础,不过缺乏实际应用价值。本文对此作了讨论,认为两种模型均有较好的物理基础,但各有自己最适合的应用范围,且两者又都具有共同的难点。

ON THE RESISTANCE MODELS OF EVAPORATION

All kinds of resistance model of evaporation, from the simple single-layer to complicated multilayer-models, have been widely applied. There is an argument in literature that single-layer models are incorrect but useful, whereas multilayer models are correct but useless. Discussion and judgement on these two kinds of model were made in this paper, both models have sound physical basis, but they are best suited for somewhat different tasks. Both types of model are therefore correct and useful within their respective sphere of approximation and applicability. Single-1 yer models are appropriate where one is concerned with vegetation essentially as a permeable lower boundary to the atmosphere (or upper boundary to the soil) in system with a length scale much larger than that of the vegetation itself; for example, in studies of the atmospheric planetary boundary layer and the atmospheric general circulation, or in hydrological modelling of medium-scale or large-scale catchments. On the other hand, multilayer models are appropriate when it is necessary to resolve detail within the canopy, either because the detail is important in its own right or because the height scale of the vegetation is comparable to that of the system under study, for example, the interaction between microclimate and physiology, or the hydrology of small forested catchments.