頁籤選單縮合
題 名 | 積水前後一維半無窮區間入滲問題之解析解=Analytical Solution of One Dimensional Infiltration Problem before and after Ponding Time |
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作 者 | 陳建謀; 陳主惠; 譚義績; | 書刊名 | 臺灣水利 |
卷 期 | 47:2=186 1999.06[民88.06] |
頁 次 | 頁20-27 |
分類號 | 443.67 |
關鍵詞 | 積水時間; 入滲曲線; 土壤體積含水比剖面; Ponding time; Infiltration curve; Water content profile; |
語 文 | 中文(Chinese) |
中文摘要 | 本文假設 Diffusivity 為常數且降雨發生後所產生之漫地流不會造成積水深度並 及及時排除情況下針對積水前後求解 Richards equation,並以砂土及黏土為例,考慮不同 降雨強度及臨前水文條件下求出積水時間、入滲曲線及土壤體積含水比剖面。於相同降雨強 度下土壤之積水時間砂土較長,而黏土較短;相同土壤不同降雨強度下之積水時間則是降雨 強度越大積水時間越短;相同的土壤於相同的降雨強度下,不同的臨前水文條件則是土壤越 乾燥則所需積水時間越長。兩種土壤之入滲曲線隨積水時間不同而有所不同,其入滲量以砂 土較大而黏土次之,砂土於不同降雨強度下之地表入滲量則是兩條入滲曲線相交前降雨強度 較大之入滲量較降雨強度較小者之入滲量為大,隨時間之增長而兩者之入滲量越趨接近。砂 土於不同臨前水文條件下之地表入滲量則是土壤越乾燥入滲量越大。數值解基本上會產生質 量平衡的問題,造成所求之準確性降低。經驗公式方面最著名為 Horton's equation,但其 並未精確考慮不同臨前水文條件及降雨強度下對入滲曲線所造成之影響,本文所推導之入滲 曲線則可將上述之影響因子納入考慮。 |
英文摘要 | In this paper, with the assumption of constant diffusivity and no ponding depth, taking the consideration of the differences of initial condition and use Richards equation as governing equation to obtain the analytical solution of infiltration curve. Previous analytical solution have been neglect the difference of initial condition during overland flow happened and before. Take the Grenoble sand and Yolo light clay as examples, sonsider different rainfall intensity and antecedent condition to get the solution of ponding time, infiltration curve and water content. Under the condition of the same rainfall intensityh, ponding time of Grenoble sand is longer than Yolo light clay. For the same soil with different rainfall intensity, the ponding time is inverse proportional to rainfall intensity. For the same soil with different antecedent condition, it takes longer to reach ponding when the antecedent condition is drier. For different soil, infiltration curve is different for the ponding time is different, the infilitration capacity for Grenoble sand is larger than Yolo light clay. For the same soil with different rainfall intensity, the infiltration capacity for high rainfall intensity is larger before the intersection of two infiltration curves, but the infiltration capacity will be almost the same in the ong run. For the same soil with different antecedent condition, the infiltration capacity for the drier one is bigger. Numerical solution may cause the problem of mass-balance, which add errors of the simulation. Horton's equation is the most famous experienced formula, but it did not consider the influence of antecedent condition and rainfall intensity to the infiltration curve. THe derivation of infiltration curve in this paper will consider the influences mentioned above. |
本系統中英文摘要資訊取自各篇刊載內容。