شبیه‌سازی منحنی رخنه عناصر خنثی و غیر جذبی با استفاده از پارامترهای هیدرولیکی خاک

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشجوی سابق کارشناسی ارشد

2 استاد گروه آبیاری و زهکشی دانشکده کشاورزی، دانشگاه شیراز

چکیده

فرایند انتقال املاح از توزیع سرعت آب در محیط متخلخل خاک تأثیر می­پذیرد و توزیع اندازه منافذ خاک از منحنی مشخصه آب خاک به کمک ضریب n یا نمای معادله منحنی مشخصه قابل پیش­بینی است که می­تواند در استنتاج توزیع سرعت آب در منافذ استفاده شود.  در این مطالعه منحنی رخنه عناصر خنثی و غیر جذبی با استفاده از پارامترهای هیدرولیکی خاک برای چهار خاک با بافت­های مختلف شبیه­سازی شد.  برای ارزیابی شبیه­سازی منحنی رخنه، نتایج آن با منحنی رخنه اندازه­گیری شده، مقایسه شد.  منحنی رخنه به دو پارامتر هیدرولیکی خاک بستگی دارد، یکی پارامتر توزیع اندازه منافذ خاک (n) است که این پارامتر از منحنی مشخصه آب خاک به­دست می­آید و دیگری پارامتر مربوط به پیوستگی خلل و فرج(m, Pore connectivity) است.  در این شبیه­سازی مقادیر m برای خاک­های مختلف بین 2- و 5- تعیین گردید.  همچنین درصد سیلت در نمونه خاک­ها، نقش مهمی در تعیین پارمتر پیوستگی خلل و فرج (m) داشته است.  براین اساس معادله­ای نیز بین میزان سیلت خاک و مقدار m برای خاک­های مختلف ارائه گردید.

کلیدواژه‌ها


عنوان مقاله [English]

Simulation Of Neutral And Non-Sorptive Breakthrough Curves Using Soil Hydraulic Parameters

چکیده [English]

Solute Transport Processes Are Affected By Soil Pore Water Velocity Distribution. Pore Size Distribution, Which Can Be Used To Infer Pore Water Velocity Distribution, Can Be Estimated From A Soil Water Retention Curve (N). In This Study, A Solute Breakthrough Curve Was Simulated Using Soil Hydraulic Parameters In Four Different Soils. To Evaluate The Proposed Model, Predictions Were Compared To That Of The Measured Soil Water Characteristics And Solute Breakthrough Data. A Breakthrough Curve Contains Two Soil Hydraulic Parameters, One Relating To Pore Size Distribution (N), Obtained From The Soil Water Retention Curve, And Pore Connectivity (M). In This Study, M Was In The Range Of -2 To -5. The Silt Content Of The Soil Can Play An Important Role In Determining Pore Connectivity, So An Equation Is Proposed For The Relationship Between Soil Silt Content And Pore Connectivity.

کلیدواژه‌ها [English]

  • Soil Water Retention Curve
  • Solute Breakthrough Curve
  • Solute Transport
Agus, F. and Cassel, D. K. 1992. Field-scale bromide transport as affected by tillage. Soil Sci. Soc. Am. J. 56: 254-260.

Brooks, R. H. and Corey, A. T. 1964. Hydraulic properties of porous media. Hydrology Paper, No. 3, Colorado State University, Fort Collins, Co., 24p.

Burdine, N. T. 1953. Relative permeability calculation from pore-size distribution data. Trans. Am. Inst. Miner. Metal. Pet. Eng. 198: 71-87.

Hatamizadeh, M. and Sepaskhah, A. R. 2007. Determination of wetting suction function and soil unsaturation hydraulic conductivity function in five soils according to one dimensional infiltration water in soil. M. Sc. Thesis, Faculty of Agriculture. Shiraz University, Iran. pp 67. (In Farsi)

Horton, R., Thompson, M. L. and McBride, J. F. 1987. Method of estimating the travel time of noninteracting solute through compacted soil material. Soil Sci. Soc. Am. J. 51: 48-53.

Jaynes, D. B., Rice, R. C. and Bowman, R. S. 1988. Independent calibration of a mechanistic-stochastic model for field-scale solute transport under flooded irrigation. Soil Sci. Soc. Am. J. 52: 1541-1546.

Jury, W. A. 1982. Simulation of solute transport using a transfer function model. Water Resour. Res. 18: 363-368.

Jury, W. A., and Roth, K. 1990. Transfer functions and solute transport through soil: theory and application. Birkhaeuser Publ., Basel, Switzerland.

Hamlen, C. J. and Kachanoski, R. G. 2004. Influence of initial and boundary conditions on solute transport through undisturbed soil columns. Soil Sci. Soc. Am. J. 68: 404-416.

Mohammadi, M. H., Neishabouri, M. R. and H. Rafahi. 2009. Predicting the solute breakthrough curve from soil hydraulic properties. Soil Sci.174(3): 165-173.

Mualem, Y. I. 1976. A new model for predicting the hydraulic conductivity of unsaturated porous media. Water Resour. Res. 3: 513-522.

Mualem, Y. I. 1978. Hydraulic conductivity on unsaturated porous media: Generalized macroscopic approach. Water Resour. Res. 2: 325-334.

Ross, P. J. and Smettem, K. R. 1993. Describing soil hydraulic properties with sum of simple function. Soil Sci. Soc. Am. J. 57: 26-29.

Roth, K., Jury, W. A., Fluhler, H. and Attinger, W. 1991. Transport of chloride through a saturated field soil. Water Resour. Res. 27: 2533-2541.

Schuh, W. M., and Cline, R. L. 1990. Effect of soil properties on unsaturated hydraulic conductivity pore-interaction factors. Soil Sci. Soc. Am. J. 54: 1509-1519.

Thorburn, P. J., and Rose, C. W. 1990. Interpretation of solute profile dynamic in irrigated soil. 3. A simple model of bypass flow in soil. Irrig. Sci. 11: 219-225.

Timlin, D. J., Ahuja, L. R., Pachepsky, Ya. A., Williams, R. D. Gimenez, D. and Rawls, W. J. 1999. Use of Brooks-Corey parameters to improve estimates of saturated conductivity from effective porosity. Soil Sci. Soc. Am. J. 63, 1086-1092.

Toride, N., and Leij, F. J. 1996. Convective-dispersive stream tube model for field scale solute transport: I. Moment analysis. Soil Sci. Soc. Am. J. 60: 342-352.

Van Genuchten, M. Th., and Wagenet, R. J. 1989. Two-site/ two-region models for pesticide transport and degradation: Theoretical development and analytical solution. Soil Sci. Soc. Am. J. 53: 1303-1310.

Van Genuchten, M. Th. 1980. A closed-form equation for predicting hydraulic conductivity of unsaturated soils. Soil Sci. Soc. Am. J. 44: 892-897.

Wang, Q., Robrt, H. and Jaehoon, L. 2002. A simple model relating soil water characteristic curve and soil solute breakthrough curve. Soil Sci. 167(7):436-443.