Evaporation from natural nonsaturated surfaces
Evaporation from natural nonsaturated surfaces
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DOI：
10.1016/0022-1694(89)90249-7
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发表时间：
1989
影响因子：
6.4
通讯作者：
R. Granger;D. Gray
中科院分区：
文献类型：
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作者：
R. Granger;D. Gray
遵循类似于 Penman (1948) 使用的发展，导出了一个通用组合方程来描述非饱和表面的蒸发。为了解释与饱和条件的偏离，该方程利用了相对蒸发的概念，即实际蒸发量与潜在蒸发量的比率，此处定义为如果表面在实际表面温度下饱和，则在现有大气条件下会发生的蒸发率。相对蒸发量与称为相对干燥功率的无量纲参数之间建立了关系，即干燥功率与干燥功率和净可用能量（净辐射加土壤热通量）之和的比率。这种关系是无量纲的并且看起来是单值的。这种关系与导出的一般蒸发方程相结合，构成了一个简单的模型，用于获得非饱和表面蒸发的估计值；不需要事先估计潜在蒸发量，并且不需要知道温度和湿度的表面条件。
Following a development similar to that used by Penman (1948) a general combination equation is derived to describe evaporation from nonsaturated surfaces. To account for departure from saturated conditions, the equation makes use of the concept of relative evaporation, the ratio of the actual to the potential evaporation, defined here as the evaporation rate which would occur under the existing atmospheric conditions if the surface were saturated at the actual surface temperature. A relationship is established between the relative evaporation and a dimensionless parameter called the relative drying power, the ratio of the drying power to the sum of the drying power and the net available energy (net radiation plus soil heat flux). The relationship is nondimensional and appears to be single-valued. The combination of this relationship with the general evaporation equation derived constitutes a simple model for obtaining estimates of evaporation from nonsaturated surfaces; no prior estimate of the potential evaporation is required, and the surface conditions of temperature and humidity need not be known.