بررسی آزمایشگاهی تأثیر دیوار آب‏‏بند بر کاهش نفوذ شوری در آبخوان‏های ساحلی با استفاده از تکنیک پردازش تصویر

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانش‌آموخته کارشناسی ارشد مهندسی عمران، گرایش مدیریت منابع آب، دانشکده مهندسی عمران، دانشگاه صنعتی جندی‌شاپور دزفول.

2 استادیار گروه آب، دانشکده مهندسی عمران، دانشگاه صنعتی جندیشاپور دزفول.

3 استادیار گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه آزاد اسلامی، واحد تهران مرکزی.

چکیده

شناخت مسئله نفوذ آب شور در آبخوان‌‏های ساحلی، نقش مؤثری بر مدیریت منابع آب زیرزمینی مناطق ساحلی دارد. در این تحقیق کاهش نفوذ شوری در یک آبخوان ساحلی در مقیاس آزمایشگاهی با در نظر گرفتن دیوار آب‌‏بند و بدون دیوار آب‏‌بند، محیط همگن و ناهمگن در حالت ماندگار بررسی شده است. برای این منظور، با تعریف سناریوهای مختلف در آزمایشگاه، پارامترهای مؤثر در مسأله در نظر گرفته شده و جهت تسهیل در تحلیل پسرفت شوری، بی‌‏بعد شدند. داده‏‌های آزمایشگاهی با استفاده از تکنیک پردازش تصویر آنالیز گردید و خطوط هم‏غلظت 5%، 95% و ناحیه انتقالی آب‏شور مابین این خطوط (ناحیه پراکندگی هیدرودینامیکی آب شور) مشخص گردید. نتایج نشان داد در محیط ناهمگن‏ میزان پیشروی گوه آب‏‌شور افزایش یافته و میزان تأثیرگذاری اجرای دیوار آب‌‏بند در محیط همگن بیشتر از محیط ناهمگن می‌‏باشد. حداکثر اثرگذاری اجرای دیوار آب‌‏بند در کاهش درصد پیشروی گوه آب شور در محیط همگن 100% و در محیط ناهمگن 92% به‏ دست آمد. بهترین محل قرارگیری دیوار آب‏‌بند در این پژوهش با توجه به ابعاد طولی 1‏ و ارتفاع 0/6 متری مخزن آزمایش، در 0/8 متری از کف و در فاصله 0/2 متری از مرز آب شور به دست آمد. از نمودارهای بی‏‌بعد حاصل می‏‌توان در طراحی بهینه دیوار آب‏‌بند در شرایط واقعی کمک گرفت.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Experimental Investigation on the Impact of Cutoff Wall on Seawater Recession in Coastal Aquifers Using Image Processing Technique

نویسندگان [English]

  • Ali Zohrabi Motlagh 1
  • Mehrdad Shahrbanouzadeh 2
  • S. Sadjad Mehdizadeh 3
1 M.Sc. Graduate in Water Resource Engineering, Department of Civil Engineering, Jundi-Shapur University of Technology, Dezful, Iran.
2 Assistant Professor, Department of Civil Engineering, Jundi-Shapur University of Technology, Dezful, Iran.
3 Assistant Professor, Department of Technology and Engineering, Islamic Azad University, Central Tehran Branch, Tehran, Iran.
چکیده [English]

Understanding the problem of seawater intrusion (SWI) in coastal aquifers plays an essential role in managing groundwater resources in these areas. This research examines seawater recession (SWR) in coastal aquifer in a laboratory scale; considering both homogeneous and heterogeneous environments, with and without a cutoff wall, and in a steady-state condition. For this purpose, different scenarios are defined in the laboratory, and all the effective parameters in the problem are considered and dimensionalized to facilitate salinity analysis. The laboratory data were analyzed using image processing technique and isolines with the concentration of 5%, 95%, and transition zone (Seawater hydrodynamic dispersion zone) were determined. The results showed that in a heterogeneous case, the rate of SWI was higher, and the efficiency of cutoff wall performance was higher in the homogenous case than the heterogeneous case. According to the present study results, the maximum effectiveness of cutoff wall in SWR percentage was obtained in 100% homogeneous and 92% for the heterogeneous case. The best location of the cutoff wall in this study with tank dimensions of 1 and 0.6 meters obtained 0.8 m from the tank bed and 0.2 m from the saline boundary. The achieved graphs helped to design the cutoff wall in actual media optimally.
 

کلیدواژه‌ها [English]

  • Seawater intrusion
  • Coastal Aquifer
  • Cutoff wall
  • Freshwater
  • Image processing technique
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