Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/5605
標題: 地表一階紊流擴散理論應用於水汽及甲烷垂直通量之量測研究
Measuring the Vertical Flux of Water Vapor and Methane by Using Aerodynamic Approach
作者: 劉其昌
Chang, Liu Chi
關鍵字: Eddy Diffusion;紊流擴散;Similarity Theory;Aerodynamic;Vertical Flux;Energy Balance;相似理論;空氣動力學;垂直通量;地表熱平衡
出版社: 環境工程研究所
摘要: 
近地表污染物之傳輸現象,與空氣品質有密不可分之關係,本研究根
據地表一階紊流擴散理論(相似理論),將用於水汽垂直通量量測之空氣
動力學方法(Aerodynamic approach) ,應用在曾文水庫水汽、東澳地
區水汽及台中市垃圾掩埋場甲烷之垂直通量的量測上;並對本法之誤差及
影響近地表大氣表面層氣體物質傳輸之氣象因子,進行初步研究。以期在
未來將此法應用於都市地區污染物垂直通量之量測上。 空氣動力學方
法乃根據相似理論、K-理論、擾動現象等,用來作垂直通量描述與量測
之方法。由於國內文獻與水汽及甲烷垂直通量相關之研究甚少,無此方面
之數據可供比較,故本研究將此方法計算過程中可得之土壤熱通量與實測
值作比較,以地表熱平衡之觀點,對量測方式進行誤差之評估,提供日後
研究改進之準則;並對造成此法誤差之可能來源,加以探討之。 根據
研究結果,於量測期間內,曾文水庫水汽垂直通量之平均值為0.019g/
square-meter/s(0.60m/year),東澳地區之平均水汽垂直通量為0.026g/
square-meter/s(0.76m/year),台中市垃圾掩埋場之平均甲烷垂直通量
為0.122mg/square-meter/s(1.06kg/ton-wet-waste)。本量測方式測得土
壤熱通量之誤差為.plmin.65%。而在理論及儀器上,複雜地形(如垃圾掩
埋場)的影響及相對溼度計的偵測極限,可能為誤差之主要來源。另外根
據敏感度分析,氣象因子對交換係數的影響以高、低層風速差最大,溫度
差次之而相對溼度差之影響最小;氣象因子對Monin Obukhov Length的
影響以高、低層溫度差最大,溼度差次之,風速差的影響最小。

The purpose of this research is to develop a technique to
measure water vapor flux and methane flux from land surface.
This technique is based on the similarity theory. Water vapor
flux from Tseng-wen reservoir,water vapor flux from a grass
land at Tungao, and methane flux from Taichung land-fill site
have been explored by using this technique. The average
water vapor flux at Tseng-wen reservoir was measured to be
0.60 m/year from Dec. 8 to Dec. 13, 1992. The average water
vapor flux at Tungao was measured to be 0.76 m per year from
Mar. 28 to Apr. 2, 1993. The methane flux at Taichung
landfill site was measured to be 0.12 mg per square meter per
second,1.06 kg per ton-waste (wet) from Feb. 26 to Feb. 28,
1993. However, special cares have to be taken to measure
flux at complex terrain such as Taichung landfill site.
This technique of flux measurement has been verified by an
energy budget method.The error of calculated soil heat flux,
which is summation of calculated latent heat flux, sensible
heat flux and measured net radiation, is determined to be
.plmin.65% in comparison with measured soil heat flux. In
addition, numerical sensitivities of calculated exchange
coefficient based on similarity theory have been conducted. It
is found that the most important factor affecting exchange
coefficient is wind speed gradient, the second dominate
factor is air temperature gradient, the third is relative
humidity gradient, and the least important factor is air
pressure.
URI: http://hdl.handle.net/11455/5605
Appears in Collections:環境工程學系所

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