| 绿洲荒漠交界处波文比能量平衡法适用性的气候学分析 |
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| 引用本文： | 黄妙芬.绿洲荒漠交界处波文比能量平衡法适用性的气候学分析[J].干旱区地理,2001,24(3):259-264. |
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| 作者姓名： | 黄妙芬 |
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| 作者单位： | 广东汕头教育学院,汕头,515041 |
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| 摘 要： | 对广泛使用的计算蒸散和显热通量的气候学方法－波文比能量平衡法在绿洲荒漠交界处的适用性从气候学角度进行分析。结果表明,波文化－能量平衡法在干旱区绿洲的平衡层内是适用的,在平衡层外及荒漠上空却失效。因而,应用波文比能量平衡法估算绿洲上的蒸发与显热时,测点的位置是至关重要的。
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| 关 键 词： | 波文比－能量平衡法 气候学 绿洲 荒漠 蒸发 显热 |
| 文章编号： | 1000-6060(2001)03-259-06 |
| 修稿时间： | 2001年3月15日 |
Climatologic Analysis of Appplicability on Bowen-ratio Energy Balance Method in the Oasis-desert Transitional zones |
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| HUANG Miao-fen.Climatologic Analysis of Appplicability on Bowen-ratio Energy Balance Method in the Oasis-desert Transitional zones[J].Arid Land Geography,2001,24(3):259-264. |
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| Authors: | HUANG Miao-fen |
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| Abstract: | The exchanges of heat and water and momentum between land surface and atmosphere are underway continuously. It is important for many actual application questions to measure these quantities, especially sensible heat and evaporation. At present there are many methods for estimating and calculating sensible heat and evaporation. Among these methods, Bowen-ratio energy balance method is most extensively applied. In this paper, the applicability of Bowen-ratio energy balance method used in the oasis-desert transitional zones is analyzed from climatologic angle. In the oasis-desert transitional zones, although oases and deserts are under the same dry climate environment, in oasis farmland the plant is luxuriant and the soil is damp because of irrigation; but in adjacent desert land the plant is sparse and the soil is dry and hardened. They form a strong contrast. Because their natures are completely different, it cause the difference of thermodynamic nature and form part of thermodynamic circulation. In surface layer, the cold and wet air stream of oases flows towards deserts; but in the air, the dry air stream of deserts flows towards oases. Because the cold and wet air stream of oases invades close to surface, it forms a "cold tongue". In deserts, while the air near surface has denatured but the air above surface has not denatured yet, it forms the phenomenon of positive temperature gradient and negative humidity gradient. From these, the results according as Bowen-ratio energy balance method are that: the consumed heat for evaporation (the item of LE) is larger than the supportable heat of surface (the item of R-G) and sensible heat transports from atmosphere to surface. These do not accord with the actual situation. It is obvious that the temperature gradient and humidity gradient are caused by the courses of both advection and vertical heat and water transportation. So Bowen-ration energy balance method based on the theory of gradient diffusion is invalid in desserts. The dry and hot air stream is not close to land surface when it enters oases. So in oases, a balance layer is formed. In this layer, the temperature gradient and humidity gradient are caused by the course of vertical heat and water transportation. If the heights of measure points are set up in this layer, Bowen-ratio energy balance method is available but out of this height it is invalid. So in the oasis-desert transitional zones, setting measure position is critical important by using Bowen-ratio energy balance method to estimate and calculate evaporation and sensible heat. |
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| Keywords: | Bowen-ratio energy balance method climatology oasis desert |
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