مدل‌سازی پاسخ جریان آب زیرزمینی در آبخوان نشتی ساحلی به نوسانات جزر و مد به روش جداسازی متغیرها و تبدیل فوریه

نوع مقاله : پژوهشی

نویسندگان

1 استادیار گروه عمران دانشکدۀ مهندسی، دانشگاه زنجان

2 دانشجوی کارشناسی ارشد مهندسی عمران، دانشگاه زنجان

چکیده

دراین مقاله روابط جدیدی برای مدل‌سازی تحلیلی پاسخ جریان آب زیرزمینی در آبخوان نشتی ساحلی به نوسانات جزر و مد به روش جداسازی متغیرها و تبدیل فوریهارائه شده است. نتایج محاسبات حل تحلیلی ارائه‌شده در این تحقیق نشان می‏دهد تأثیر جزر و مد در فواصل نزدیک به ساحل بیشتر است و با دور‌شدن از ساحل، مقدار نوسانات سطح آب زیرزمینی کمتر می‏شود. با توجه به بررسی انجام‏‌شده، افزایش مقدار قابلیت انتقال سبب افزایش هد هیدرولیکی سطح آب زیرزمینی می‏شود. این تغییرات مادامی که قابلیت انتقال کمتر از  است، محسوس‏تر است اما با چند‌برابر شدن مقدار قابلیت انتقال، میزان افزایش هد هیدرولیکی سطح آب زیرزمینی کمتر است. همچنین با افزایش مقدار تغذیۀ هد سطح آب زیرزمینی افزایش می‏یابد. تأثیر افزایش مقدار قابلیت انتقال و تغذیه بر افزایش هد هیدرولیکی در فواصل نزدیک به ساحل کمتر و در اواسط مسیر در فاصلۀ 30 تا 75 متری از مرز جزر و مدی بیشتر است. علاوه بر این‌ها، نتایج مدل‌سازی روابط جدید ارائه‌شده در این تحقیق با نتایج مدل نرم‌‏افزار مادفلو مقایسه شد. این مقایسه نشان داد حل تحلیلی ارائه‌شده در این پژوهش بسیار کارآمد است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Modelling the Groundwater Flow Response to Tidal Fluctuation in a Coastal Leaky Aquifer by separation of variables and Fourier transformation

نویسندگان [English]

  • Iraj Saeedpanah 1
  • Somayeh Mohammadzade Roofchaee 2
1 Assistant Professor Department of Civil Engineering ,University of Zanjan
2 M.Sc. student Hydraulic Structures, Civil Engineering ,University of Zanjan
چکیده [English]

In this paper, groundwater response to tidal effects in a Coastal Leaky Aquifer is simulated via analytical solutions. The solutions are obtained by application of separation of variables method and Fourier transform method. It is shown that those points of the aquifer near to the coastal shore are much more influenced by the tidal fluctuations in the boundary than the rest of the aquifer. The amplitude of tidal change is significant at points of the aquifer near to the coastal shore and gets smaller with distance from the boundary. In addition, it is shown that groundwater level increases with rises in transmissivity. This phenomenon is more significant when transmissivity is less than 400 m2/hr . Also, the groundwater head rises with rises in recharge rate. The effect of variations in transmissivity and recharge rate on hydraulic head is more significant at points located between 30 and 75 meters and less significant at points near to the coastal shore. The presented analytical solution is compared and verified with those results obtained from MODFLOW.

کلیدواژه‌ها [English]

  • Analytical solution
  • Coastal leaky aquifer
  • Groundwater Flow
  • Tide
  • Method of separation of variables and Fourier transformation
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