張力滲透計應用於蓮華池五號集水區土壤水力傳導度測定分析

Analysis of Soil Hydraulic Conductivity Measured by Tension Infiltrometer in Lienhwachi Watershed No. 5

陳明杰(Ming-Chieh Chen) ； 黃襦慧(Ju-Hui Huang)

《中華林學季刊》 39卷2期 (2006/06) Pp. 207-220

https://doi.org/10.30064/QJCF.200606.0005

摘要

本研究為了探討林地土壤在不飽和狀態下水分滲透的特性，應用張力滲透計量測現地滲透率，分析不同壓力水頭條件下的水力傳導度。研究區域位於蓮華池五號集水區東向坡面，依照山脊、山腹、山谷分別選定四個位置，每一個位置分別對深度0 cm、20 cm、40 cm實施滲透試驗，同時，採取不擾動土壤試體分析物理性質，供對照現地滲透試驗結果，說明孔隙率對水分滲透流動的影響。土壤總孔隙率與粗孔隙率測定結果，皆以深度0 cm 為最高，經變異數分析結果，不同深度之間皆呈現顯著的差異。由於粗孔隙中水分的流動相當快速，使得水力傳導度產生明顯變化，深度0 cm的總孔隙率與粗孔隙率含量較高，飽和水力傳導度較高，隨著壓力水頭降低，水力傳導度大幅降低，而深度20 cm和40 cm的總孔隙率與粗孔隙率含量較低，則變化較為緩和。經變異數分析結果，不同深度之間水力傳導度呈現顯著的差異。當壓力水頭大於-10 cm時，三個深度之水力傳導度以深度0 cm為最高，然而小於-10 cm時，則以深度0 cm為最低。壓力水頭從0 cm降至-5 cm時，三個深度之水力傳導度降低幅度大於壓力水頭低於-5 cm時的降低幅度。

關鍵字

張力滲透計 ； 水力傳導度 ； 蓮華池

並列摘要

This study was to investigate the soil infiltration characteristics of forest land in unsaturated condition. Tension infiltrometer was employed to measure the field infiltration rates according to different pressure head that was used to analyze hydraulic conductivity (K). Study area is located at eastern slope of Lienhwachi watershed No. 5. Four locations from ridge, hillslope, and valley were chosen and each location comprised soil depths of 0 cm, 20cm, and 40 cm were selected for field infiltration test. Meanwhile, undisturbed soil samples near to infiltration test point were extracted for analyzing physical properties. Both of the results were compared to explain the influence of porosity on soil infiltration characteristics. From soil porosity measurement, total porosity and coarse porosity of soil depth of 0 cm was more than other depths, and that there were also significantly different between depths from analysis of variance. Soil water movement in coarse pore was swift that made K change obviously. Soil depth of 0 cm contained more total porosity and coarse porosity ratios, which K decreased remarkably on pressure head decreased, but soil depth of 20 cm and 40 cm also decreased moderately because of containing fewer total porosity and coarse porosity ratios. From analysis of variance of K, there was significantly difference between depths but not discernible between locations. K of soil depth of 0 cm was larger than other depths on pressure head higher than -10 cm H2O, but smaller than other depths on lower than -10 cm H2O. Also, K of three soil depths decreased more remarkably on pressure head changed from 0 cm H2O to -5 cm H2O than other pressure head changed.

並列關鍵字

Tension infiltrometer ； Hydraulic conductivity ； Lienhwachi