本文主要以理論及實驗探討定水頭狀態下，土壤入滲於水平面與坡面實際入滲情況之差異。本文之理論分析是假設坡面入滲符合一維Green-Ampt方程式，入滲方向為與坡面垂直之方向，此方向為入滲初期主要受毛細力影響時之方向，因此透過理論式可了解主要受毛細力主導之時期。 為配合Green-Ampt方程式之入滲性質(均質性且等向性)，本研究採用Hele-Shaw模型實驗，且Hele-Shaw模型濕鋒內為飽和液體，可清楚判別及量測飽和濕鋒曲線；本文也針對實際土壤入滲情況做砂箱實驗，採用台灣九號砂來進行實驗，透過實驗不但能了解入滲變化過程，更可以與理論式之適用性做探討。 由實驗結果得知理論式之適用範圍為初期之入滲部分，對於長時間 入滲較不適用，因為入滲一段時間後會逐漸受到重力效應之影響，使得入滲方向偏移至重力方向，因此定義一參數式加以判別入滲受重力影響顯著之時期。 The infiltration processes across both the horizontal plane and the sloping surface under ponding condition are experimentally examined in this study. The Green-Ampt equation proposed by Chen and Young(2006) is compared with experimental data.. In one-dimensional case, infiltration along the normal direction is mainly controlled by capillary forces. A Hele-Shaw model was established, which satisfies the condition of homogeneous and isotropic for the Green-Ampt assumption. The saturated wetting front depth can be measured with the Hele-Shaw model approach. On the other hand, a sand-box experiment was established to observe real infiltration cases. According to the experimental data, the Green-Ampt model is only applicable at the beginning stage. The deviations between Green-Ampt model and experimental results become obvious afterwards due to gravitational effect. A dimensionless parameter define the time factor between the influence of capillary force and the gravity is proposed in this study.
