Effect of Water Table Level and Soil Layering on Hydraulic Conductivity and Inverse Air Entry Suction Using Tension Disc

Document Type : Research Paper

Authors

Abstract

Hydraulic conductivity is one of the important physical properties of the soil used extensively in water and soil science. Most of the soil processes take place in unsaturated soil conditions. This study was conducted in order to evaluate the effect of soil layering and water table on saturated and unsaturated hydraulic parameters using a tension disc in five suction heads, i.e. 0, 5, 10, 15, and 20 cm. The experimental tests were done on three same samples with 56 cm diameter and 85 cm height in three compacted layers with soil bulk densities of 1.18, 1.38 and 1.68 gr.cm-3 and water table depths of 85 (no water table) 50, and 25 cm.  Additionally, we considered a one-layered sample to investigate the effect of bulk density. The experimental results showed that soil layering caused changes in the values ​​of saturated and unsaturated hydraulic conductivity. Also, sensitivity of the saturated hydraulic conductivity to soil layering was more than that of the inverse air entry suction(α). Compared with the treatment with no water table, the saturated hydraulic conductivity of the layered soil in treatments with water table depths of 25 cm and 50 cm decreased by 52 % and 27.6 %, respectively.

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  1. بای بوردی، م. (1378). اصول مهندسی زهکشی وبهسازی خاک. چاپ هشتم، انتشارات دانشگاه تهران.
  2. بی­باک، ه. ع.، کشکولی، ح. ع.، و ناصری ع. ا.(1389 ). تخمین هدایت هیدرولیکی خاک ماسه­ای در مجاورت سطح ایستابی با استفاده از دستگاه نفوذ سنج دیسک. سومین همایش مدیریت شبکه­های آبیاری و زهکشی، اسفند 89، دانشکده علوم و مهندسی آب، اهواز.
  3. سازمان مدیریت و برنامه­ریزی کشور( 1384). دستورالعمل تعیین هدایت هیدرولیکی خاک به روش­های مختلف، نشریه 322.
  4. غفاری، پ.، کشکولی، ح. ع. و مختاری، ن. ر. 1386. مقایسه روش­های اندازه­گیری هدایت هیدرولیکی با استفاده از نفوذ سنج گلف و نفوذ سنج مکشی. نهمین سمینار ملی آبیاری و کاهش تبخیر، کرمان.
  5. قبادیان، ر. و محمدی، ک. 1389. مقایسه روش­های مختلف آنالیز پرمامتر گلف جهت محاسبه ضریب هدایت هیدرولیکی صحرایی خاک لوم سیلتی در بالای سطح ایستابی. نشریه آب وخاک، جلد 24، شماره 3، صفحه­های 511-501.
  6. Ankeny M, Kaspar TC and Horton R. (1988). Design for an automated tension infiltrometer. Soil Science Society of America Journal,52:893-896.
  7. Ankeny, M. D., Ahmed, M., Kaspar, T.C. and Horton, R. (1991). Simple field method for determining unsaturated hydraulic conductivity. Soil Science Society of America Journal, 55:467-470.
  8. Brooks, . H. and Corey A.T. (1964). Hydraulic properties of porous media. Colorado State University, Fort Collins, Colorado, No. 3: 37 p.
  9. Clothier, B. and White I. (1981). Measurement of sorptivity and soil water diffusivity in the field. Soil Science Society of America Journal, 45:241-245
  10. Dixon, M. L. (1975). Soil survey of Borden County, United States. Soil Conservation Service and Texas Agricultural Experiment Station, Texas Journal, 68: 26 p.
  11. Durner, W. and Lipsius, K. (2005). Determining soil hydraulic properties. Encyclopedia of Hydrological Sciences. John Wiley & Sons, Ltd.
  12. Iwata, S., Tabuchi, T. and Warkentin, B.P. (1995). Soil-water interactions, mechanisms and applications.New York. ISBN 0-8247-9293-9. 440 pp.
  13. Jarvis, N. and Messing, I. (1995). Near-saturated hydraulic conductivity in soils of contrasting texture measured by tension infiltrometers. Soil Science Society of America Journal,59:27-34
  14. Lin, L., Chen, J. and Zhang, Z. (2011). Design of automated disc infiltrometer based on differential transducer. Transducer and Microsystem Technologies, 2-29.
  15. Logsdon, S. and Jaynes, D. (1993). Methodology for determining hydraulic conductivity with tension infiltrometers.SoilScience Society of America Journal,57:1426-1431
  16. Lu, N. and Likos, W.J. (2004). Unsaturated soil mechanics. New Jersey: John Wiley and Sons Inc.
  17. Marsel, S.G. and Leij , F.J.( 2000). Improved Prediction of Unsaturated Hydraulic Conductivity with the Mualem-van Genuchten Model. Soil Sci. Soc. Am. J, 64: 843–851.
  18. Mohanty, B. P. and Mousli, Z. (2000). Saturated hydraulic conductivity and soil water retention properties across a soil-slope transition. Water Resources Research,36:3311-3324.
  19. Perroux, K. and White, I. (1988). Designs for disc permeameters. Soil Science Society of America Journal,52:1205-1215.
  20. Rafael, A. Vandervaere, J., Roulier, S., Thony, J., Gaudet, J. and Vauclin, M. (2000). Field measurement of soil surface hydraulic properties by disc and ring infiltrometers: A review and recent developments. Soil and Tillage Research, 55:1-29.
  21. Reynolds, W. and Elrick, D. (1985). In situ measurement of field-saturated hydraulic conductivity, sorptivity, and the alpha-parameter using the guelph permeameter. Soil Science,140:292-302.
  22. Reynolds, W., Bowman, B., Brunke, R., Drury, C. and Tan, C. (2000). Comparison of tension infiltrometer, pressure infiltrometer, and soil core estimates of saturated hydraulic conductivity. Soil Science Society of America Journal, 64(2): 478-484.
  23. Reynolds, W. and Elrick, D. (1991). Determination of hydraulic conductivity using a tension infiltrometer. Soil Science Society of America Journal,55:633-639.
  24. Schwartz, R. and Evett, S. (2002). Estimating hydraulic properties of a fine-textured soil using a disc infiltrometer. Soil Science Society of America Journal,66:1409-1423.
  25. Scotter, D., Clothier, B. and Harper, E. (1982). Measuring saturated hydraulic conductivity and sorptivity using twin rings. Soil Research, 20 (4): 295-304.
  26. Smettem, K., Ross, P., Haverkamp, R. and Parlange, J. (1995). Three-Dimensional Analysis of Infiltration from the Disk Infiltrometer: 3 Parameter Estimation Using a Double-Disk Tension Infiltrometer. Water Resources Research,31:2491-2495.
  27. Wooding, R. A. (1968). Steady infltration from large shallow circular pond, Water Resources Research, 4, 1259-1273.