傳統上保水曲線在靜止狀態下量測。但許多實驗證據發現飽和度與毛
細壓力的關係，在改變不同邊界條件下排水速度會有所不同，因排水速度
不同改變的保水曲線稱為保水曲線的動態效應。但張力計本身並不能及時
反應水壓的快速變化，張力計的延遲不可避免會對量測造成影響，而實驗
量測動態毛細壓力卻大多忽略張力計延遲效應。本研究進行一系列室內沙
箱實驗量測靜態和動態保水曲線。並且透過實驗量化延遲係數 k。探討影
響延遲係數的因素。此外進行沙柱排水實驗量測累積出流量，來了解靜態
和動態保水曲線和張力計延遲效應對模擬一維排水的影響。
研究結果發現，在修正毛細壓力後靜態和動態保水曲線的差異更為明
顯。修正後的保水曲線，VG 參數 n 增加但α卻減少，使得採用修正前與
修正後保水曲線模擬的一維排水累積出流量之間差異不大。模擬結果顯示
流量1.11cm3/s 的動態保水曲線用於模擬沙柱排水，與實驗結果最為相
近。延遲係數的測試實驗結果發現，陶瓷頭經長時間使用會造成其延遲係
數會減少，延遲係數與玻璃砂顆粒大小成反比，以及延遲係數隨有效飽和
度增加而增加。

Traditionally, the water retention curve is measured at rest. However, the experimental evidence found that the desaturation rate changes the water retention curve known as the dynamic effect of water retention curve. It is difficult to observe the dynamic effect because the tensiometer itself does not respond to the rapid changes in water pressure. The tensiometer delay will inevitably have an impact on the measurement, while the experimental measurement of dynamic capillary pressure mostly ignores the tensiometer delay effect. In this study, a series of indoor sandbox experiments were performed to measure static and dynamic water retention curves, and we also perform the experiments to quantify the delay coefficient k. To explore the factors that affect the delay factor. In addition, the sand column drainage experiment was conducted to measure the cumulative flow rate to understand the effects of static and dynamic water retention curves and tensor delay effects on simulated one-dimensional drainage simulation.
The results show that the static and dynamic water retention curves are more pronounced after the modified capillary pressure by considering delay effects. Nevertheless, the VG parameters of the modified water retention curve n increases but the α is reduced, making the difference between the simulated one-dimensional drainage of the cumulative outflows with the original and modified water retention curve is insignificant. The simulation results show that the simulated sand column drainage with the dynamic water retention curve with a flow rate of 1.11 cm3/s is closest to the experimental results. The result of the experiments for delay coefficient shows that the delay coefficient of the ceramic head significantly reduced when the head has been used for a long time, the delay coefficient decreases as the decrease of the glass sand size increases, and
the delay coefficient increases with the effective saturation.

1.劉煜彤，液體與沙粒特性對動態毛細壓力與入滲現象影響之觀測，碩士論文，國立中央大學，2015
2.Anwar, A. H. M. F., & Thien, L. C. (2015). Investigating Leachate Transport at Landfill Site Using HYDRUS-1D. International Journal of Environmental Science and Development, 6(10), 741-745. doi:10.7763/ijesd.2015.v6.691
3.Assefa, K. A., & Woodbury, A. D. (2013). Transient, spatially varied groundwater recharge modeling. Water Resources Research, 49(8), 4593-4606. doi:10.1002/wrcr.20332
4.Barenblatt, G. I., Patzek, T. W., & Silin, D. B. (2003). The Mathematical Model of Nonequilibrium Effects in Water-Oil Displacement. Spe Journal, 8(04), 409-416. doi:10.2118/87329-pa
5.Bogena, H. R., Huisman, J. A., Oberdörster, C., & Vereecken, H. (2007). Evaluation of a low-cost soil water content sensor for wireless network applications. Journal of Hydrology, 344(1-2), 32-42. doi:10.1016/j.jhydrol.2007.06.032
6.Brooks, R. H., & Corey, A. T. (1964). Hydraulic Properties of Porous Media and Their Relation to Drainage Design. Transactions of the ASAE, 7(1), 0026-0028. doi:10.13031/2013.40684
7.Camps-Roach, G., O'Carroll, D. M., Newson, T. A., Sakaki, T., & Illangasekare, T. H. (2010). Experimental investigation of dynamic effects in capillary pressure: Grain size dependency and upscaling. Water Resources Research, 46(8), n/a-n/a. doi:10.1029/2009wr008881
8.Elzeftawy, A., & Mansell, R. S. (1975). Hydraulic Conductivity Calculations for Unsaturated Steady-State and Transient-State Flow in Sand1. Soil Science Society of America Journal, 39(4), 599. doi:10.2136/sssaj1975.03615995003900040013x
9.Hassanizadeh, S. M., Celia, M. A., & Dahle, H. K. (2002). Dynamic Effect in the Capillary Pressure-Saturation Relationship and its Impacts on Unsaturated Flow. Vadose Zone Journal, 1(1), 38-57. doi:10.2136/vzj2002.3800
10.Hassanizadeh, S. M., & Gray, W. G. (1990). Mechanics and Thermodynamics of Multiphase Flow in Porous-Media Including Interphase Boundaries. Advances in Water Resources, 13(4), 169-186. doi:Doi 10.1016/0309-1708(90)90040-B
11.Hassanizadeh, S. M., & Gray, W. G. (1993). Thermodynamic Basis of Capillary-Pressure in Porous-Media. Water Resources Research, 29(10), 3389-3405. doi:Doi 10.1029/93wr01495
12.Hassanizadeh, S. M., M.A. Celia, and H.K. Dahle. (1993). Toward an improved description of the physics of two-phase flow. Advances in Water Resources, 16(1), 53-67. doi:10.1016/0309-1708(93)90029-f
13.Hou, L., Chen, L., & Kibbey, T. C. G. (2012). Dynamic capillary effects in a small-volume unsaturated porous medium: Implications of sensor response and gas pressure gradients for understanding system dependencies. Water Resources Research, 48(11), n/a-n/a. doi:10.1029/2012wr012434
14.Juanes, R. (2008). Nonequilibrium effects in models of three-phase flow in porous media. Advances in Water Resources, 31(4), 661-673. doi:10.1016/j.advwatres.2007.12.005
15.Kalaydjian, F. J. M. (1994). Dynamic Capillary Pressure Curve for Water/Oil Displacement in Porous Media: Theory vs. Experiment.
16.Klute, A., & Gardner, W. R. (1962). Tensiometer response time. Soil Science, 93(3), 204-207.
17.Manthey, S. (2006). Two-phase flow processes with dynamic effects in porous media - parameter estimation and simulation. doi:http://dx.doi.org/10.18419/opus-253
18.Mokady, R. S., & Low, P. F. (1964). The Tension-Moisture Content Relationship Under Static and Dynamic Conditions. Soil Science Society of America Journal, 28(4), 583. doi:10.2136/sssaj1964.03615995002800040040x
19.Poulovassilis. (1974). The uniqueness of the moisture characters. Journal of Soil Science, 25(1), 27-33.
20.Richards, L. A. (1931). Capillary Conduction of Liquids through Porous Mediums. Physics, 1(5), 318-333. doi:10.1063/1.1745010
21.Sakaki, T., O'Carroll, D. M., & Illangasekare, T. H. (2010). Direct Quantification of Dynamic Effects in Capillary Pressure for Drainage-Wetting Cycles. Vadose Zone Journal, 9(2), 424-437. doi:10.2136/vzj2009.0105
22.Schelle, H., Heise, L., Janicke, K., & Durner, W. (2013). Water retention characteristics of soils over the whole moisture range: a comparison of laboratory methods. European Journal of Soil Science, 64(6), 814-821. doi:10.1111/ejss.12108
23.Selker, J., Leclerq, P., Parlange, J. Y., & Steenhuis, T. (1992). Fingered flow in two dimensions: 1. Measurement of matric potential. Water Resources Research, 28(9), 2513-2521. doi:10.1029/92WR00963
24.Šimůnek, J., van Genuchten, M.Th. and Šejna, M. (2013). The HYDRUS-1D Software Package for Simulating the One-Dimensional Movement of Water, Heat, and Multiple Solutes in Variably-Saturated Media
25.Smiles, D. E., Vachaud, G., & Vauclin, M. (1971). A Test of the Uniqueness of the Soil Moisture Characteristic During Transient, Nonhysteretic Flow of Water in a Rigid Soil1. Soil Science Society of America Journal, 35(4), 534. doi:10.2136/sssaj1971.03615995003500040018x
26.Stauffer, F. (1978). Time dependence of the relations between capillary pressure, water content and conductivity during drainage of porous media.
27.Tafteh, A., & Sepaskhah, A. R. (2012). Application of HYDRUS-1D model for simulating water and nitrate leaching from continuous and alternate furrow irrigated rapeseed and maize fields. Agricultural Water Management, 113, 19-29. doi:10.1016/j.agwat.2012.06.011
28.Topp, G. C., Klute, A., & Peters, D. B. (1967). Comparison of Water Content-Pressure Head Data Obtained by Equilibrium, Steady-State, and Unsteady-State Methods. Soil Science Society of America Journal, 31(3), 312-314. doi:10.2136/sssaj1967.03615995003100030009x
29.Towner, G. D. (1980). THEORY OF TIME RESPONSE OF TENSIOMETERS. Journal of Soil Science, 31(4), 607-621. doi:10.1111/j.1365-2389.1980.tb02108.x
30.Towner, G. D. (1981). The response of tensiometers embedded in saturated soil peds of low hydraulic conductivity. Journal of Agricultural Engineering Research, 26(6), 541-549. doi:http://dx.doi.org/10.1016/0021-8634(81)90086-X
31.Vachaud, G., Vauclin, M., & Wakil, M. (1972). A Study of the Uniqueness of the Soil Moisture Characteristic During Desorption by Vertical Drainage1. Soil Science Society of America Journal, 36(3), 531-532. doi:10.2136/sssaj1972.03615995003600030044x
32.van Genuchten, M. T. (1980). A Closed-form Equation for Predicting the Hydraulic Conductivity of Unsaturated Soils1. Soil Science Society of America Journal, 44(5), 892. doi:10.2136/sssaj1980.03615995004400050002x
33.Wildenschild, D., Hopmans, J. W., & Simunek, J. (2001). Flow rate dependence of soil hydraulic characteristics. Soil Science Society of America Journal, 65(1), 35-48.