蓮華池四號集水區土壤物理性質與水力傳導度的特性

Characteristics of Soil Physical Properties and Hydraulic Conductivity of Lienhwachi Watershed No.4

陳明杰(Ming-Chieh Chen) ； 洪志遠(Chin-Yuan Hung)

《國立臺灣大學生物資源暨農學院實驗林研究報告》 21卷4期 (2007/12) Pp. 293-306

https://doi.org/10.6542/EFNTU.200712_21(4).0003

摘要

本研究探討林地土壤的物理性質，及其影響土壤水力傳導度的特性。以蓮華池四號集水區為對象，使用張力滲透計進行土壤表層以及深度20cm之入滲試驗，分析不同壓力水頭條件下水力傳導度的變化，並且，採取不擾動土壤試體，供分析土壤物理性質。土壤取樣分析的資料經變異數分析結果，容積密度、坋粒含量、粘粒含量、碳含量、總孔隙率、大孔隙率（相當於壓力水頭大於-3cm）、中孔隙率（相當於壓力水頭-3cm~-100cm）等，在深度之間皆呈顯著差異，而取樣位置之間則差異不顯著。入滲試驗結果，由於土壤表層的總孔隙率與大孔隙率含量較高，當壓力水頭大於-10cm時，土壤表層的水力傳導度較深度20cm為高，然而小於-10cm時則土壤表層較低，經變異數分析結果，深度之間的水力傳導度呈顯著差異，而不同位置之間則差異不顯著。其次，飽和水力傳導度與土壤物理性質有關，相關分析結果，飽和水力傳導度與總孔隙率、大孔隙率、中孔隙率、碳含量等呈顯著正相關，與容積密度、坋粒含量呈顯著負相關，以容積密度等六項獨立變數建立估計飽和水力傳導度的指數型複迴歸方程式，在5%的顯著水準下迴歸方程式具顯著性，亦即容積密度等六項獨立變數對迴歸模型具有解釋能力。

關鍵字

土壤物理性質 ； 水力傳導度 ； 張力滲透計 ； 蓮華池

並列摘要

This study is to investigate the characteristics of soil physical properties and their related effects on hydraulic conductivity of forest land in Lienhwachi watershed No. 4. The field infiltration rates of soil surface and depth of 20 cm were measured by tension infiltrometer, where hydraulic conductivity were determined under different water pressure head. Soil physical properties, including bulk density, silt content, clay content, carbon content, macroporosity (at the pressure head above -3cm H2O), and mesoporosity (at the pressure head range from -3cm to -100 cm H2O), were measured from the adjacent soils next to the infiltration test location. Our results showed that bulk density, silt content, clay content, carbon content, total porosity, macroporosity and mesoporosity, were significantly different with different soil depth, but no discernible difference was observed at different locations. According to the infiltration results, saturated hydraulic conductivity (Ks) of soil surface was larger than that of depth of 20cm because of its high total porosity and macroporosity. Unsaturated hydraulic conductivity (K) of soil surface was also larger than that of depth of 20cm at the pressure head higher than -10cm H2O, but was smaller at the pressure head lower than -10cm H2O. Ks was significantly and positively correlated with total porosity, macroporosity, mesoporosity and carbon content, but negatively correlated with bulk density and silt content. An exponential multiple regression equation was found between Ks and soil physical properties which revealed the capability of predicting Ks by using these six independent variables derived from soil physical properties.

並列關鍵字

Hydraulic conductivity ； Lienhwachi ； Soil physical property ； Tension infiltrometer.