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題 名 | 未飽和層土壤水份遲滯效應之研究=The Effect of Hysteresis on Moisture in Unsaturated Soil |
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作 者 | 黃漢誠; 陳主惠; 譚義績; | 書刊名 | 農業工程學報 |
卷 期 | 46:4 2000.12[民89.12] |
頁 次 | 頁33-47 |
分類號 | 434.222 |
關鍵詞 | 遲滯現象; 保水曲線; 水力傳導係數; 比水容積; Hysteresis; Soil-moisture-retention curve; Hydraulic conductivity; Specific water capacity; |
語 文 | 中文(Chinese) |
中文摘要 | 在未飽和土壤水份的傳輸現象中,水份移動的水力特性是相當重要的,此特性取決於土壤含水量及土壤類型等因素,未飽和土壤水份會因乾燥、濕潤交替的歷程而發生遲滯現象,一般在土壤水份估計的計算上,多未能真實反應實際的土壤水份變化情形,要能準確的計算則須在乾燥、濕潤歷程交替變化環境中考慮遲滯現象的發生及其所造成之未飽和水力傳導係數、比水容積及保水特性的變動。 本文基於van Genuchten(1980)土壤保水曲線模式及Mualem(1976)未飽和水力傳導係數模式,加以推演使之可運用於遲滯問題,透過簡單便捷的方式計算遲滯效應對對土壤水力特性的影響,透過五組土壤保水實驗數據與模式預測之比較,探討未飽和土壤之保水特性、水力傳導係數及比水容積在乾燥、濕潤歷程下的變化;研究顯示在乾燥、濕潤交替循環的歷程中土壤之未飽和水力特性的變化並非以唯一關係存在,在實際環境中應加以考慮,本文提出之土壤水份保水曲線模式能適度反應?滯現象之土壤水份變化情形。並且比水容積與張力水頭的關係可得較準確之估計,而模式所推演之未飽和水力傳導係數可將乾燥、濕潤狀態之水份傳輸關係明朗化。 |
英文摘要 | In order to solve the transport of water in the unsaturated soil, the hydraulic property must be available, that property is very much dependent on the moistures and nature of soils. In unsaturated soils, hysteresis is an important phenomenon affecting water flow, and the effect should be taking into account during wetting and drying processes. Hysteresis has important effects in the filed and can not be neglected. Most studies are ignored about hysteresis because of compilation. The prediction of soil water balance can be improved by taking hysteresis into account under diurnally varying environmental conditions that involved alternative wetting and drying. The model based on a combination of van Genuchten’s parametric model (1980) and mualem’s parametric model (1976), we estimate the hysteresis models of unsaturated hydraulic conductivity and specific capacity in the unsaturated soil when infiltration and evaporation. |
本系統中英文摘要資訊取自各篇刊載內容。