聖奧古斯汀草地蒸發散量不同估測方法之比較

Comparison of Different Methods in Evapotranspiration Estimation from St. Augustine Pasture

唐琦(Chi Tang) ； 徐森雄(Sen-Hsiung Hsu) ； 陳俐伶(Li-Ling Chen)

《作物、環境與生物資訊》 4卷2期 (2007/06) Pp. 151-160

https://doi.org/10.30061/CEB.200706.0007

摘要

本研究自2005年10月至2006年6月於國立屏東科技大學教學氣象站觀測坪周遭一面積約為0.39ha之聖奧古斯汀草地，設置一2m高度之鐵塔進行氣溫、相對濕度、風速、淨輻射量、地中傳導熱量及土壤水分含量等微氣象因子觀測，先利用大型蒸發皿測得之蒸發量檢核土壤水分含量變化所估測之草地實際蒸發散量(ET(下標 a))合理性，再分與熱收支法(ET(下標 H))、淨輻射量(ET(下標 N))及作物係數(ET(下标 C))經驗法所推估蒸發散量進行比較分析。結果得知：自然生長條件下之聖奧古斯汀草地，ET(下標 H)及ET(下標 N)較ET(下標 a)有偏高情形，另與ET(下標 C)相近，而各法之蒸發散量推估值與ET(下標 a)間之相關性均達1%顯著水準。

關鍵字

聖奧古斯汀草地 ； 蒸發散量 ； 土壤水分收支

並列摘要

This study aimed at using different methods to estimate evapotranspiration of St. Augustine (Stenotaphrum secundatum) pasture. The experimental site was located near the Meteorological Station at National Pingtung University of Science and Technology, with an area of 0.38ha (97min length and 42m in width). The soil moisture deficiency at the depths of 0.05, 0.1, 0.2, 0.5, and 1m under ground surface was measured to calculate the actual evapotranspiration (ET(subscript a)), and its accuracy was examined by a large evaporation tank. The observational tower of 2m height was situated in the center of pasture, and the micro-meteorological measurements included air temperature, relative humidity, wind speed, net radiation and soil heat flux. The measured data were used as inputs to predict evapotranspiration by heat budget method (ET(subscript H)), empirical method of net radiation (ET(subscript N)), and crop coefficient (ET(subscript C)). The predicted values were then compared with values of ET(subscript a) for their accuracy evaluation. The experimental period was started from October 2005 to June 2006. Results indicated that ET(subscript H) and ET(subscript N) were overestimated when there was no irrigation applied to the St. Augustine pasture. The ET(subscript C) was closed to ET(subscript a) (within＜4mm). All the predicted evapotranspiration were higher than ET(subscript a) (P＜1%) during the experimental period.

並列關鍵字

St. Augustine pasture ； Evapotranspiration ； Soil moisture balance