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題 名 | 灌溉缺水時期淺層地下水毛管上升對作物需水之補助=Upward Movement of Capillary from Shallow Groundwater to Supplement Crop Water Requirement in Irrigation Deficit Period |
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作 者 | 張文亮; | 書刊名 | 農業工程學報 |
卷 期 | 44:3 1998.09[民87.09] |
頁 次 | 頁25-37 |
分類號 | 443.52 |
關鍵詞 | 毛管上升; 缺水灌溉; Capillary uptake; Deficiency irrigation; |
語 文 | 中文(Chinese) |
中文摘要 | 以節水灌溉的觀點,淺層地下水毛管上升是不可忽視的自然水源。在豐水期的土 壤水分深層滲漏,可視為地面水對淺層地下水之補助。在枯水期,地表土壤的水分枯乾,與 淺層地下水間產生的壓力水頭差,能使毛管水移動至地表,供地表蒸散所需。本研究將毛管 上升分為非穩定態與穩定態二階段,並以理論推導毛管上升在不同階段的運動方程式,配合 實驗室以70公分與200公分之土柱,觀測毛管上升高度與通量之變化。實驗室的觀測結果學 甲旱作田間試驗站之觀察,證明當毛管上升適量趨於穩定態時,毛管上升是夠供旱作根區田 間容水量的土壤水分,使地表面0∼7cm的深度有高於凋萎點的土壤水分。其毛管上升通量為 1.0mm/day,近似2/3的飽和導水係數。以毛管水分的上升通量與毛管上升區的土壤剖面水分 分佈,這些水量不足以提供旱作最大生產量,但可避免作物缺水逆境,提供最經濟的產量。 |
英文摘要 | Capillary uptake from shallow groundwater shall be considered as an important water resource for irrigation supplementation. During wet period, level of shallow groundwater is closed to soil surface from deep percolation. However, during dry period, capillary uptake may bring large amount of water up to soil surface by pressure gradient, thus to make up deficiency of evaportranspiration. In this study, capillary movement is categorized to steady and unsteady state and movement equations are derived from Darcy's Law. 70cm-and 200 cm-soil-columns are used as apparatus for capillary uptake investigation. Investigated results were compared with field observation in Hsueh-Chia Upland Crop Experimental Station. This comparison showed that capillary uptake can supply soil water higher than field capacity in root zone, and the soil water is also higher than wetting point in 0-7cm soil surface under steady condition. Flux of capillary uptake is 1.0mm/day closed to two thirds of the saturated hydraulic conductivity. Based on flux of capillary uptake and soil water distribution, amount of capillary water cannot make maximum yield production but reach optimum yield production economically. |
本系統中英文摘要資訊取自各篇刊載內容。