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.

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
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