土壤未飽和層點源滲漏之數值試驗

Numerical Experiment of Point Source Percolation in Unsaturated Soil

許少華(Shaohua Marko Hsu) ； 辜國讚(Gwo-Tzann Gu)

《中華水土保持學報》 28卷4期 (1997/12) Pp. 279-287

https://doi.org/10.29417/JCSWC.199712_28(4).0002

摘要

本硏究乃利用二維Richards方程式，配合van Genuchten＆Niel（1985）土壤特性曲線關係式，透過交替變換方向的數值方法（A. D. I.）來模擬未飽和層點源滲漏之現象，數値解先以砂箱試驗驗證。然後將起始條件改爲含水量處於重力平衡狀況下的條件，再重覆此數值試驗，結果顯示出起始含水量的差異對濕鋒的發展有明顯的影響，此結果顯示數值試驗的方便性與必要性。

關鍵字

滲漏 ； 未飽和土層 ； 濕鋒

並列摘要

Vertical two-dimensional Richard's equation is solved numerically to simulate percolation behavior from 8 point source of water. Simulation set-up is made similar to the sand-tank experiments performed by Chen and Yu (1996 ), in which water were injected near the top surface of a tank of relative dry soil. van Genuchten & Nielsen's (1985) formulas are employed to represent relationships between hydraulic conductivity, moisture content, and pressure head of unsaturated soil. Alternating directional implicit (ADI) scheme is used to solve this 2-D problem. Result shows that this model is capable of reproducing experimental results as well as other information which are either hidden or difficult to measure.

並列關鍵字

Percolation ； Unsaturated Soil ； Wet Front