集水區植物蒸發散率之測定

The Evapotranspirtion Rate ,from the Watersheds in ,Taiwan

楊居成(Jiu-sherng Yang)

《中華水土保持學報》 10卷1期 (1979/07) Pp. 93-114

https://doi.org/10.29417/JCSWC.197907_10(1).0006

摘要

本試驗分別於台灣省石門水庫集水區，國立中興大學校園，及台灣省林試所蓮華池集水試驗區進行。利用水分擴散阻礙儀及露點測定儀分別測定植物之水分蒸散率，以求得較可靠之數值。所得結果如下:(1)樹種間之蒸散率最大相差80倍。(2)總平均蒸散率介於0.3至2.0x 10^(-6)ml H_2O•cm^(-2)．min^(-1)之間。(3)於自然條件下，水分擴散阻礙儀測得之植樹平均蒸散率大於露點測定儀所得之1.5～6倍。(4)林地表面年平均蒸發量為29.80 mm。(5)植物年平均蒸散量為147.84mm; 於枯水期中， 平均植物年蒸發散損失率為24.26%，可施用抗蒸散劑或落葉劑等處理後，以減少植物蒸散率，以增加有效水量。

並列摘要

The transpiration rates from three different areas were determined with water diffusion resistance meter and dew point hygrometer. The results indicate that: (1) There is .about 80 times difference between the lowest and the highest transpiration rates of plant leaves. (2) The range of the total average transpiration rates is between 0.3 x 10^(-4) and 2.0 x 10^(-4) ml H_2O cm^(-2) min^(-1). (3) The transpiration rates determined by water diffusion resistance meter is higher 1.5 to 6 times than those measured by dew point hygrometer. (4) The calculated average evaporation rate of the forest surface is equal to 29.80 mm. year^(-1). (5) The calculated average evapotranspiration rate of the three 100m^2 quadrates is equal. to 177.64mm.year^(-1). The average lost race from evapotranspiration for dry season is equal to 24.26%. The data indicate that the total available water from the watershed may be increased by reducing the transpiration rate of the plant leaf via the application of antitranspirant or abscising agent on the watershed plants.