關刀溪森林集水區氣象因子及氣候指標之探討

Meteorological Factors and Climatic Index in Guandaushi Forest Watershed

游繁結(Fan-Chieh Yu) ； 詹宜紋(I-Wen Geng)

《中華水土保持學報》 32卷1期 (2001/03) Pp. 9-16

https://doi.org/10.29417/JCSWC.200103_32(1).0002

摘要

本研究係以關刀溪森林集水區爲對象，就長期收集之氣象資料，探討集水區林內與林外各氣象因子之關係，並初步建立集水區之氣候指標，茲將分析結果摘要如下：1.本試區林內日射量約爲林外日射量的49％，此乃因林內受茂密樹冠阻隔及吸收部分的日射，使得林內日射量較林外低。而林內淨輻射變化之趨勢大致與日射之變化趨勢符合，林外淨輻射之變化則不隨日射高低而有明顯之起伏。2.本試區林內之平均氣溫爲16.8℃，林外之平均氣溫爲19.5℃，顯見植物對於近地氣溫有顯著調節之效果；而林內外之氣溫在夏季時相差較小，冬季時相差較大。3.本試區林內由於樹冠之蔽蔭作用且植物蒸散量大，使得相對濕度全年皆維持於92％以上；林外相對濕度則較林內爲低，約維持於80％～90％之間。4.本試區林內由於山谷效應的影響，使得冬季時其風速有呈現增大之情形；林外因較開曠，故風速較爲穩定，無明顯之高低起伏。5.氣候指標之分析結果，以氣溫及相對濕度較適合作爲本集水區之氣候指標。

關鍵字

日射 ； 氣溫 ； 相對濕度 ； 風速 ； 氣候指標 ； 林內 ； 林外

並列摘要

The long-term meteorological data in Guaudaushi Forest Watershed were used to analyze the relationships among the meteorological factors in this study. The watershed climatic index was also developed. The results were summarized as follows: 1. The solar radiation inside the forest was about 49% of the outside because the dense canopy intercepted and absorbed partial solar radiation. The variation tendency of net radiation inside the forest conformed to the tendency of solar radiation, but outside it did not. 2. The mean air temperature was 16.8℃ inside the forest and 19.5℃ outside t he forest. The difference in air temperature was small in summer, but large during winter. 3. The relative humidity inside the forest was kept more than 92% all over the year because of the shelter of canopy and of the large evapotranspiration of vegetation. The relative humidity outside the forest was kept 80%~90%. 4. The wind velocity inside the forest was higher because of the wind blowing along the valley. The wind velocity outside was lower because of the opening topography. 5. Air temperature and relative humidity were suggested to be regarded as climatic indices in Guandaushi forest watershed.

並列關鍵字

solar radiation ； air temperature ； relative humidity ； wind velocity ； climatic index ； inside the forest ； outside the forest