查詢結果分析
來源資料
頁籤選單縮合
題名 | 利用終端反射TDR方法探討土壤之未飽和傳輸特性=Unsaturated Soil Water Characteristics using End Termination of Time Domain Reflectometry Method |
---|---|
作者 | 蘇苗彬; 曾介君; 陳旺志; Su, Maiu-bin; Zeng, Jie-jun; Chen, Wang-jyu; |
期刊 | 水土保持學報 |
出版日期 | 19981200 |
卷期 | 30:4 1998.12[民87.12] |
頁次 | 頁339-353 |
分類號 | 434.222 |
語文 | chi |
關鍵詞 | 未飽和土壤; 傳輸; 時域反射原理; Unsaturated soil; Hydraulic conductivity; Time domain reflectometry; |
中文摘要 | 未飽和層水的移動過程相當複雜,很難定量加以描述。其中,水力傳導度的獲得 ,一般常用間接量測或數值分析等方式來求取。 本研究即採間接量測之方式, 以終端反射 TDR 方法結合小尺寸張力計,分別量測含水量及張力,藉此來探討未飽和層的傳輸特性。 資料分析是將不同時間所測得之電壓值轉換成張力值,以量得的反射係數定出含水量隨時間 變化情形。進而擷取相同時段之張力與含水量以構成保水曲線,在不同時段用瞬間剖面之觀 念計算求得水力傳導度 k( θ )。 由試驗結果顯示,以 TDR 終端設置來量測反射係數確能得知瞬間含水量之變化。 土柱試驗 的結果可看出未飽和層之遲滯趨勢,並獲得水力傳導度為隨體積含水量變化之函數。因此, TDR 結合張力計的使用,確為一套可完整同時求得 k( θ ) 與保水曲線之量測系統。 |
英文摘要 | Unsaturated flow of soil water is very complex and difficult to describe quantitatively. The unsaturated hydraulic conductivity k function can often be obtain by the indirect method or the numerical analysis. This research adopts an indirect method by coordinating the "end termination of time domain reflectometry method" and minitensiometer to measure volume water content θ and suction Ψ in order to study the characteristic of unsaturated flow. The major content including: (1) Tensiometer calibration: finding the relationship between voltage (mV) and Ψ (2) Installing eight SMA sensors around soil box to measure response coefficient (p); and then we can determine p-θ (3) Soil column test: Getting soil-moisure retention curve and k by measuring θ and Ψ. Data analysis is made by transforming different time measured mV into suction Ψ. The volume water contents θ are changing with time differences because of the measured p. Further more, we can pick numbers of Ψ and θ at the same time in order to structure the soil-measure retention curve. With different time periods, k can be calculated with instantaneous profile method. Therefore, together with TDR and tensiometer can form an integrated measure system to get the k and the soil-measure retention curve simultaneously. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。