砾石含量对於不同土壤之饱和水力传导度之影响EffectofGravel.PDF

礫石含量對於不同土壤之飽和水力傳導度之影響 (1) (2)* (3) 王琮元 林俐玲 蔡義誌 摘 要 自然化育的土壤內大多含有礫石，均質土壤與異質土壤之飽和水力傳導度因而有所差異。 本研究使用砂土藉由添加不同體積百分含量的礫石，觀察其水力傳導度的變化情形。使用的礫 石含量介於5%-50% ，飽和水力傳導度採用定水頭實驗，並且利用壓力鍋排水實驗計算土體中粗 孔隙度(macroporosity ) 。實驗結果指出，隨著礫石含量的增加，水力傳導度也隨之增加。而實 ∗ 驗中亦發現飽和水力傳導度與”粗孔隙度與總孔隙度之比值 ， ” ，呈現正相關。本研究另外 分析砂質壤土與坋質壤土，發現砂質壤土與砂土在礫石體積百分含量與飽和水力傳導度之間有 相同的趨勢 ；而坋質壤土則是體積含量增加，水力傳導度下降 。推測其原因為細質地土壤其細 ∗ ∗ 孔隙較多 ，故 上升和緩 ，而礫石增加曲折度變大，所造成的影響較 大，導致水力傳導度下 降。 關鍵詞( ：粗孔隙度 ，孔隙比，礫石含量，飽和水力傳導度 ) Effect of Gravel Content on Saturated Hydraulic Conductivity in Different Soil Texture Li-Ling Lin(1) Tsung- Yuan Wang(2) Yi-Zhih Tsai(3) (1) (2) (3) Graduate student , Professor and Doctor of Philosophy Department of Soil and Water Conservation National Chung Hsing University, Taichung, Taiwan 402, R.O.C. ABSTRACT In natural condition, there are gravel content in the soil. The saturated hydraulic conductivity between the homogeneous soil and heterogeneous soil are quite different. Sand with different gravel content soil samples were chosen as the experiment materials in this research. The saturated hydraulic conductivity of different treatment was measured.The gravel volume content was between 5%-50%. The saturated hydraulic conductivity was measured in constant head condition. The macroporosity in sample was measured by draining in pressureplate experiment .The results indicated that, the saturated hydraulic conductivity would increase with the increased gravel amount.During the draining in pressureplate experiment, we found that the saturated h